PyInstaller Manual

Version: PyInstaller 3.1.dev0+0371db4.mod
Authors: David Cortesi
based on structure by Giovanni Bajo & William Caban
based on Gordon McMillan's manual
Copyright: This document has been placed in the public domain.


In Brief

PyInstaller bundles a Python application and all its dependencies into a single package. The user can run the packaged app without installing a Python interpreter or any modules. PyInstaller supports Python 2.7 and Python 3.3+, and correctly bundles the major Python packages such as numpy, PyQt, Django, wxPython, and others.

PyInstaller is tested against Windows, Mac OS X, and Linux. However, it is not a cross-compiler: to make a Windows app you run PyInstaller in Windows; to make a Linux app you run it in Linux, etc. PyInstaller has been used successfully with AIX, Solaris, and FreeBSD, but is not tested against them.

What's New This Release

Release 3.0 is a major rewrite that adds Python 3 support, better code quality through use of automated testing, and resolutions for many old issues.

Functional changes include removal of support for Python prior to 2.7, an easier way to include data files in the bundle (Adding Files to the Bundle), and changes to the "hook" API (Understanding PyInstaller Hooks).



PyInstaller runs in Windows XP or newer. It can create graphical windowed apps (apps that do not need a command window).

PyInstaller requires the PyWin32 or pypiwin32 Python extension for Windows. If you install PyInstaller using pip, and PyWin32 is not found, pypiwin32 is automatically installed.

The pip-Win package is also recommended but not required.

Mac OS X

PyInstaller runs in Mac OS X 10.6 (Snow Leopard) or newer. It can build graphical windowed apps (apps that do not use a terminal window). PyInstaller builds apps that are compatible with the Mac OS X release in which you run it, and following releases. It can build 32-bit binaries in Mac OS X releases that support them.


PyInstaller requires the ldd terminal application to discover the shared libraries required by each program or shared library. It is typically found in the distribution-package glibc or libc-bin.

It also requires the objdump terminal application to extract information from object files. This is typically found in the distribution-package binutils.

AIX, Solaris, and FreeBSD

Users have reported success running PyInstaller on these platforms, but it is not tested on them. The ldd and objdump commands are needed.

Before using PyInstaller in these systems you must compile a bootloader; see Building the Bootloader.


PyInstaller is distributed under the GPL License but with an exception that allows you to use it to build commercial products:

  1. You may use PyInstaller to bundle commercial applications out of your source code.
  2. The executable bundles generated by PyInstaller from your source code can be shipped with whatever license you want.
  3. You may modify PyInstaller for your own needs but changes to the PyInstaller source code fall under the terms of the GPL license. That is, if you distribute your modifications you must distribute them under GPL terms.

For updated information or clarification see our FAQ at the PyInstaller home page.

How To Contribute

PyInstaller is an open-source project that is created and maintained by volunteers. At you find links to the mailing list, IRC channel, and Git repository, and the important How to Contribute link. Contributions to code and documentation are welcome, as well as tested hooks for installing other packages.

How to Install PyInstaller

PyInstaller is a normal Python package. You can download the archive from PyPi, but it is easier to install using pip where is is available, for example:

pip install pyinstaller

or upgrade to a newer version:

pip install --upgrade pyinstaller

Installing in Windows

For Windows, PyWin32 or the more recent pypiwin32, is a prerequisite. The latter is installed automatically when you install PyInstaller using pip or easy_install. If necessary, follow the pypiwin32 link to install it manually.

It is particularly easy to use pip-Win to install PyInstaller along with the correct version of PyWin32. pip-Win also provides virtualenv, which makes it simple to maintain multiple different Python interpreters and install packages such as PyInstaller in each of them. (For more on the uses of virtualenv, see Supporting Multiple Platforms below.)

When pip-Win is working, enter this command in its Command field and click Run:

venv -c -i  pyi-env-name

This creates a new virtual environment rooted at C:\Python\pyi-env-name and makes it the current environment. A new command shell window opens in which you can run commands within this environment. Enter the command

pip install PyInstaller

Once it is installed, to use PyInstaller,

  • Start pip-Win
  • In the Command field enter venv pyi-env-name
  • Click Run

Then you have a command shell window in which commands such as pyinstaller execute in that Python environment.

Installing in Mac OS X

PyInstaller works with the default Python 2.7 provided with current Mac OS X installations. However, if you plan to use a later version of Python, or if you use any of the major packages such as PyQt, Numpy, Matplotlib, Scipy, and the like, we strongly recommend that you install these using either MacPorts or Homebrew.

PyInstaller users report fewer problems when they use a package manager than when they attempt to install major packages individually.

Installing from the archive

If pip is not available, download the compressed archive from PyPI. If you are asked to test a problem using the latest development code, download the compressed archive from the develop branch of PyInstaller Downloads page.

Expand the archive. Inside is a script named Execute python install with administrator privilege to install or upgrade PyInstaller.

For platforms other than Windows, Linux and Mac OS, you must first build a bootloader program for your platform: see Building the Bootloader. After the bootloader has been created, use python install with administrator privileges to complete the installation.

Verifying the installation

On all platforms, the command pyinstaller should now exist on the execution path. To verify this, enter the command

pyinstaller --version

The result should resemble 3.n for a released version, and 3.n.dev0-xxxxxx for a development branch.

If the command is not found, make sure the execution path includes the proper directory:

  • Windows: C:\PythonXY\Scripts where XY stands for the major and minor Python verysion number, for example C:\Python34\Scripts for Python 3.4)
  • Linux: /usr/bin/
  • OS X (using the default Apple-supplied Python) /usr/bin
  • OS X (using Python installed by homebrew) /usr/local/bin
  • OS X (using Python installed by macports) /opt/local/bin

To display the current path in Windows the command is echo %path% and in other systems, echo $PATH.

Installed commands

The complete installation places these commands on the execution path:

If you do not perform a complete installation (installing via pip or executing, these commands will not be installed as commands. However, you can still execute all the functions documented below by running Python scripts found in the distribution folder. The equivalent of the pyinstaller command is pyinstaller-folder/ The other commands are found in pyinstaller-folder /cliutils/ with meaningful names (, etc.)

What PyInstaller Does and How It Does It

This section covers the basic ideas of PyInstaller. These ideas apply to all platforms. Options and special cases are covered below, under Using PyInstaller.

PyInstaller reads a Python script written by you. It analyzes your code to discover every other module and library your script needs in order to execute. Then it collects copies of all those files -- including the active Python interpreter! -- and puts them with your script in a single folder, or optionally in a single executable file.

For the great majority of programs, this can be done with one short command,


or with a few added options, for example a windowed application as a single-file executable,

pyinstaller --onefile --windowed

You distribute the bundle as a folder or file to other people, and they can execute your program. To your users, the app is self-contained. They do not need to install any particular version of Python or any modules. They do not need to have Python installed at all.


The output of PyInstaller is specific to the active operating system and the active version of Python. This means that to prepare a distribution for:

  • a different OS
  • a different version of Python
  • a 32-bit or 64-bit OS

you run PyInstaller on that OS, under that version of Python. The Python interpreter that executes PyInstaller is part of the bundle, and it is specific to the OS and the word size.

Analysis: Finding the Files Your Program Needs

What other modules and libraries does your script need in order to run? (These are sometimes called its "dependencies".)

To find out, PyInstaller finds all the import statements in your script. It finds the imported modules and looks in them for import statements, and so on recursively, until it has a complete list of modules your script may use.

PyInstaller understands the "egg" distribution format often used for Python packages. If your script imports a module from an "egg", PyInstaller adds the egg and its dependencies to the set of needed files.

PyInstaller also knows about many major Python packages, including the GUI packages Qt (imported via PyQt or PySide), WxPython, TkInter, Django, and other major packages. For a complete list, see Supported Packages.

Some Python scripts import modules in ways that PyInstaller cannot detect: for example, by using the __import__() function with variable data, or manipulating the sys.path value at run time. If your script requires files that PyInstaller does not know about, you must help it:

  • You can give additional files on the pyinstaller command line.
  • You can give additional import paths on the command line.
  • You can edit the myscript.spec file that PyInstaller writes the first time you run it for your script. In the spec file you can tell PyInstaller about code modules that are unique to your script.
  • You can write "hook" files that inform PyInstaller of hidden imports. If you create a "hook" for a package that other users might also use, you can contribute your hook file to PyInstaller.

If your program depends on access to certain data files, you can tell PyInstaller to include them in the bundle as well. You do this by modifying the spec file, an advanced topic that is covered under Using Spec Files.

In order to locate included files at run time, your program needs to be able to learn its path at run time in a way that works regardless of whether or not it is running from a bundle. This is covered under Run-time Operation.

PyInstaller does not include libraries that should exist in any installation of this OS. For example in Linux, it does not bundle any file from /lib or /usr/lib, assuming these will be found in every system.

Bundling to One Folder

When you apply PyInstaller to the default result is a single folder named myscript. This folder contains all your script's dependencies, and an executable file also named myscript (myscript.exe in Windows).

You compress the folder to and transmit it to your users. They install the program simply by unzipping it. A user runs your app by opening the folder and launching the myscript executable inside it.

It is easy to debug problems that occur when building the app when you use one-folder mode. You can see exactly what files PyInstaller collected into the folder.

Another advantage of a one-folder bundle is that when you change your code, as long as it imports exactly the same set of dependencies, you could send out only the updated myscript executable. That is typically much smaller than the entire folder. (If you change the script so that it imports more or different dependencies, or if the dependencies are upgraded, you must redistribute the whole bundle.)

A small disadvantage of the one-folder format is that the one folder contains a large number of files. Your user must find the myscript executable in a long list of names or among a big array of icons. Also your user can create a problem by accidentally dragging files out of the folder.

How the One-Folder Program Works

A bundled program always starts execution in the PyInstaller bootloader. This is the heart of the myscript executable in the folder.

The PyInstaller bootloader is a binary executable program for the active platform (Windows, Linux, Mac OS X, etc.). When the user launches your program, it is the bootloader that runs. The bootloader creates a temporary Python environment such that the Python interpreter will find all imported modules and libraries in the myscript folder.

The bootloader starts a copy of the Python interpreter to execute your script. Everything follows normally from there, provided that all the necessary support files were included.

(This is an overview. For more detail, see The Bootstrap Process in Detail below.)

Bundling to One File

PyInstaller can bundle your script and all its dependencies into a single executable named myscript (myscript.exe in Windows).

The advantage is that your users get something they understand, a single executable to launch. A disadvantage is that any related files such as a README must be distributed separately. Also, the single executable is a little slower to start up than the one-folder bundle.

Before you attempt to bundle to one file, make sure your app works correctly when bundled to one folder. It is is much easier to diagnose problems in one-folder mode.

How the One-File Program Works

The bootloader is the heart of the one-file bundle also. When started it creates a temporary folder in the appropriate temp-folder location for this OS. The folder is named _MEIxxxxxx, where xxxxxx is a random number.

The one executable file contains an embedded archive of all the Python modules used by your script, as well as compressed copies of any non-Python support files (e.g. .so files). The bootloader uncompresses the support files and writes copies into the the temporary folder. This can take a little time. That is why a one-file app is a little slower to start than a one-folder app.

After creating the temporary folder, the bootloader proceeds exactly as for the one-folder bundle, in the context of the temporary folder. When the bundled code terminates, the bootloader deletes the temporary folder.

(In Linux and related systems, it is possible to mount the /tmp folder with a "no-execution" option. That option is not compatible with a PyInstaller one-file bundle. It needs to execute code out of /tmp.)

Because the program makes a temporary folder with a unique name, you can run multiple copies of the app; they won't interfere with each other. However, running multiple copies is expensive in disk space because nothing is shared.

The _MEIxxxxxx folder is not removed if the program crashes or is killed (kill -9 on Unix, killed by the Task Manager on Windows, "Force Quit" on Mac OS). Thus if your app crashes frequently, your users will lose disk space to multiple _MEIxxxxxx temporary folders.


Do not give administrator privileges to a one-file executable (setuid root in Unix/Linux, or the "Run this program as an administrator" property in Windows 7). There is an unlikely but not impossible way in which a malicious attacker could corrupt one of the shared libraries in the temp folder while the bootloader is preparing it. Distribute a privileged program in one-folder mode instead.


Applications that use os.setuid() may encounter permissions errors. The temporary folder where the bundled app runs may not being readable after setuid is called. If your script needs to call setuid, it may be better to use one-folder mode so as to have more control over the permissions on its files.

Using a Console Window

By default the bootloader creates a command-line console (a terminal window in Linux and Mac OS, a command window in Windows). It gives this window to the Python interpreter for its standard input and output. Your script's use of print and input() are directed here. Error messages from Python and default logging output also appear in the console window.

An option for Windows and Mac OS is to tell PyInstaller to not provide a console window. The bootloader starts Python with no target for standard output or input. Do this when your script has a graphical interface for user input and can properly report its own diagnostics.

Hiding the Source Code

The bundled app does not include any source code. However, PyInstaller bundles compiled Python scripts (.pyc files). These could in principle be decompiled to reveal the logic of your code.

If you want to hide your source code more thoroughly, one possible option is to compile some of your modules with Cython. Using Cython you can convert Python modules into C and compile the C to machine language. PyInstaller can follow import statements that refer to Cython C object modules and bundle them.

Additionally, Python bytecode can be obfuscated with AES256 by specifying an encryption key on PyInstaller's command line. Please note that it is still very easy to extract the key and get back the original bytecode, but it should prevent most forms of "casual" tampering.

Using PyInstaller

The syntax of the pyinstaller command is:

pyinstaller [options] script [script ...] | specfile

In the most simple case, set the current directory to the location of your program and execute:


PyInstaller analyzes and:

In the dist folder you find the bundled app you distribute to your users.

Normally you name one script on the command line. If you name more, all are analyzed and included in the output. However, the first script named supplies the name for the spec file and for the executable folder or file. Its code is the first to execute at run-time.

For certain uses you may edit the contents of myscript.spec (described under Using Spec Files). After you do this, you name the spec file to PyInstaller instead of the script:

pyinstaller myscript.spec

You may give a path to the script or spec file, for example

pyinstaller options... ~/myproject/source/

or, on Windows,

pyinstaller "C:\Documents and Settings\project\myscript.spec"


General Options

-h, --help show this help message and exit
-v, --version Show program version info and exit.
--distpath=DIR Where to put the bundled app (default: ./dist)
 Where to put all the temporary work files, .log, .pyz and etc. (default: ./build)
-y, --noconfirm
 Replace output directory (default: SPECPATH/dist/SPECNAME) without asking for confirmation
 Path to UPX utility (default: search the execution path)
-a, --ascii Do not include unicode encoding support (default: included if available)
--clean Clean PyInstaller cache and remove temporary files before building.
 Amount of detail in build-time console messages (default: INFO, choose one of DEBUG, INFO, WARN, ERROR, CRITICAL)

What to generate

-F, --onefile Create a one-file bundled executable.
-D, --onedir Create a one-folder bundle containing an executable (default)
--specpath=DIR Folder to store the generated spec file (default: current directory)
-n NAME, --name=NAME
 Name to assign to the bundled app and spec file (default: first script's basename)

How to generate

-d, --debug Tell the bootloader to issue progress messages while initializing and starting the bundled app. Used to diagnose problems with missing imports.
-s, --strip Apply a symbol-table strip to the executable and shared libs (not recommended for Windows)
--noupx Do not use UPX even if it is available (works differently between Windows and *nix)

Windows and Mac OS X specific options

-c, --console, --nowindowed
 Open a console window for standard i/o (default)
-w, --windowed, --noconsole
 Windows and Mac OS X: do not provide a console window for standard i/o. On Mac OS X this also triggers building an OS X .app bundle.This option is ignored in *NIX systems.
-i <FILE.ico or FILE.exe,ID or FILE.icns>, --icon=<FILE.ico or FILE.exe,ID or FILE.icns>
 FILE.ico: apply that icon to a Windows executable. FILE.exe,ID, extract the icon with ID from an exe. FILE.icns: apply the icon to the .app bundle on Mac OS X

Windows specific options

 add a version resource from FILE to the exe
-m <FILE or XML>, --manifest=<FILE or XML>
 add manifest FILE or XML to the exe
 Add or update a resource of the given type, name and language from FILE to a Windows executable. FILE can be a data file or an exe/dll. For data files, at least TYPE and NAME must be specified. LANGUAGE defaults to 0 or may be specified as wildcard * to update all resources of the given TYPE and NAME. For exe/dll files, all resources from FILE will be added/updated to the final executable if TYPE, NAME and LANGUAGE are omitted or specified as wildcard *.This option can be used multiple times.
--uac-admin Using this option creates a Manifest which will request elevation upon application restart.
--uac-uiaccess Using this option allows an elevated application to work with Remote Desktop.

Windows Side-by-side Assembly searching options (advanced)

 Any Shared Assemblies bundled into the application will be changed into Private Assemblies. This means the exact versions of these assemblies will always be used, and any newer versions installed on user machines at the system level will be ignored.
 While searching for Shared or Private Assemblies to bundle into the application, PyInstaller will prefer not to follow policies that redirect to newer versions, and will try to bundle the exact versions of the assembly.

Mac OS X specific options

 Mac OS X .app bundle identifier is used as the default unique program name for code signing purposes. The usual form is a hierarchical name in reverse DNS notation. For example: com.mycompany.department.appname (default: first script's basename)

Shortening the Command

Because of its numerous options, a full pyinstaller command can become very long. You will run the same command again and again as you develop your script. You can put the command in a shell script or batch file, using line continuations to make it readable. For example, in Linux:

pyinstaller --noconfirm --log-level=WARN \
    --onefile --nowindow \
    --hidden-import=secret1 \
    --hidden-import=secret2 \
    --upx-dir=/usr/local/share/ \

Or in Windows, use the little-known BAT file line continuation:

pyinstaller --noconfirm --log-level=WARN ^
    --onefile --nowindow ^
    --hidden-import=secret1 ^
    --hidden-import=secret2 ^
    --icon-file=..\MLNMFLCN.ICO ^

Using UPX

UPX is a free utility available for most operating systems. UPX compresses executable files and libraries, making them smaller, sometimes much smaller. UPX is available for most operating systems and can compress a large number of executable file formats. See the UPX home page for downloads, and for the list of supported executable formats. Development of UPX appears to have ended in September 2013, at which time it supported most executable formats except for 64-bit binaries for Mac OS X. UPX has no effect on those.

A compressed executable program is wrapped in UPX startup code that dynamically decompresses the program when the program is launched. After it has been decompressed, the program runs normally. In the case of a PyInstaller one-file executable that has been UPX-compressed, the full execution sequence is:

  • The compressed program start up in the UPX decompressor code.
  • After decompression, the program executes the PyInstaller bootloader, which creates a temporary environment for Python.
  • The Python interpreter executes your script.

PyInstaller looks for UPX on the execution path or the path specified with the --upx-dir option. If UPX exists, PyInstaller applies it to the final executable, unless the --noupx option was given. UPX has been used with PyInstaller output often, usually with no problems.

Encrypting Python Bytecode

To encrypt the Python bytecode modules stored in the bundle, pass the --key=key-string argument on the command line.

For this to work, you must have the PyCrypto module installed. The key-string is a string of 16 characters which is used to encrypt each file of Python byte-code before it is stored in the archive inside the executable file.

Supporting Multiple Platforms

If you distribute your application for only one combination of OS and Python, just install PyInstaller like any other package and use it in your normal development setup.

Supporting Multiple Python Environments

When you need to bundle your application within one OS but for different versions of Python and support libraries -- for example, a Python 3 version and a Python 2.7 version; or a supported version that uses Qt4 and a development version that uses Qt5 -- we recommend you use virtualenv. With virtualenv you can maintain different combinations of Python and installed packages, and switch from one combination to another easily. (If you work only with Python 3.4 and later, the built-in script pyvenv does the same job.)

  • Use virtualenv to create as many different development environments as you need, each with its unique combination of Python and installed packages.
  • Install PyInstaller in each environment.
  • Use PyInstaller to build your application in each environment.

Note that when using virtualenv, the path to the PyInstaller commands is:

  • Windows: ENV_ROOT\Scripts
  • Others: ENV_ROOT/bin

Under Windows, the pip-Win package installs virtualenv and makes it especially easy to set up different environments and switch between them. Under Linux and Mac OS, you switch environments at the command line.

Supporting Multiple Operating Systems

If you need to distribute your application for more than one OS, for example both Windows and Mac OS X, you must install PyInstaller on each platform and bundle your app separately on each.

You can do this from a single machine using virtualization. The free virtualBox or the paid VMWare and Parallels allow you to run another complete operating system as a "guest". You set up a virtual machine for each "guest" OS. In it you install Python, the support packages your application needs, and PyInstaller.

The Dropbox system is useful with virtual machines. Install a Dropbox client in each virtual machine, all linked to your Dropbox account. Keep a single copy of your script(s) in a Dropbox folder. Then on any virtual machine you can run PyInstaller thus:

cd ~/Dropbox/project_folder/src # Linux, Mac -- Windows similar
rm *.pyc # get rid of modules compiled by another Python
pyinstaller --workpath=path-to-local-temp-folder  \
            --distpath=path-to-local-dist-folder  \
            ...other options as required...       \

PyInstaller reads scripts from the common Dropbox folder, but writes its work files and the bundled app in folders that are local to the virtual machine.

If you share the same home directory on multiple platforms, for example Linux and OS X, you will need to set the PYINSTALLER_CONFIG_DIR environment variable to different values on each platform otherwise PyInstaller may cache files for one platform and use them on the other platform, as by default it uses a subdirectory of your home directory as its cache location.

It is said to be possible to cross-develop for Windows under Linux using the free Wine environment. Further details are needed, see How to Contribute.

Making Linux Apps Forward-Compatible

Under Linux, PyInstaller does not bundle libc (the C standard library, usually glibc, the Gnu version) with the app. Instead, the app expects to link dynamically to the libc from the local OS where it runs. The interface between any app and libc is forward compatible to newer releases, but it is not backward compatible to older releases.

For this reason, if you bundle your app on the current version of Linux, it may fail to execute (typically with a runtime dynamic link error) if it is executed on an older version of Linux.

The solution is to always build your app on the oldest version of Linux you mean to support. It should continue to work with the libc found on newer versions.

The Linux standard libraries such as glibc are distributed in 64-bit and 32-bit versions, and these are not compatible. As a result you cannot bundle your app on a 32-bit system and run it on a 64-bit installation, nor vice-versa. You must make a unique version of the app for each word-length supported.

Capturing Windows Version Data

A Windows app may require a Version resource file. A Version resource contains a group of data structures, some containing binary integers and some containing strings, that describe the properties of the executable. For details see the Microsoft Version Information Structures page.

Version resources are complex and some elements are optional, others required. When you view the version tab of a Properties dialog, there's no simple relationship between the data displayed and the structure of the resource. For this reason PyInstaller includes the pyi-grab_version command. It is invoked with the full path name of any Windows executable that has a Version resource:

pyi-grab_version executable_with_version_resource

The command writes text that represents a Version resource in readable form to standard output. You can copy it from the console window or redirect it to a file. Then you can edit the version information to adapt it to your program. Using pyi-grab_version you can find an executable that displays the kind of information you want, copy its resource data, and modify it to suit your package.

The version text file is encoded UTF-8 and may contain non-ASCII characters. (Unicode characters are allowed in Version resource string fields.) Be sure to edit and save the text file in UTF-8 unless you are certain it contains only ASCII string values.

Your edited version text file can be given with the --version-file= option to pyinstaller or pyi-makespec. The text data is converted to a Version resource and installed in the bundled app.

In a Version resource there are two 64-bit binary values, FileVersion and ProductVersion. In the version text file these are given as four-element tuples, for example:

filevers=(2, 0, 4, 0),
prodvers=(2, 0, 4, 0),

The elements of each tuple represent 16-bit values from most-significant to least-significant. For example the value (2, 0, 4, 0) resolves to 0002000000040000 in hex.

You can also install a Version resource from a text file after the bundled app has been created, using the set_version command:

set_version version_text_file executable_file

The set_version utility reads a version text file as written by pyi-grab_version, converts it to a Version resource, and installs that resource in the executable_file specified.

For advanced uses, examine a version text file as written by pyi-grab_version. You find it is Python code that creates a VSVersionInfo object. The class definition for VSVersionInfo is found in utils/win32/ in the PyInstaller distribution folder. You can write a program that imports versioninfo. In that program you can eval the contents of a version info text file to produce a VSVersionInfo object. You can use the .toRaw() method of that object to produce a Version resource in binary form. Or you can apply the unicode() function to the object to reproduce the version text file.

Building Mac OS X App Bundles

If you specify only --onefile under Mac OS X, the output in dist is a UNIX executable myscript. It can be executed from a Terminal command line. Standard input and output work as normal through the Terminal window.

If you also specify --windowed, the dist folder contains two outputs: the UNIX executable myscript and also an OS X application named

As you probably know, an application is a special type of folder. The one built by PyInstaller contains a folder always named Contents. It contains:

  • A folder Frameworks which is empty.
  • A folder MacOS that contains a copy of the same myscript UNIX executable.
  • A folder Resources that contains an icon file.
  • A file Info.plist that describes the app.

PyInstaller builds minimal versions of these elements.

Use the osx-bundle-identifier= argument to add a bundle identifier. This becomes the CFBundleIdentifier used in code-signing (see the PyInstaller code signing recipe and for more detail, the Apple code signing overview technical note).

Use the icon= argument to specify a custom icon for the application. (If you do not specify an icon file, PyInstaller supplies a file icon-windowed.icns with the PyInstaller logo.)

You can add items to the Info.plist by editing the spec file; see Spec File Options for a Mac OS X Bundle below.

Making Mac OS X apps Forward-Compatible

In Mac OS X, components from one version of the OS are usually compatible with later versions, but they may not work with earlier versions.

The only way to be certain your app supports an older version of Mac OS X is to run PyInstaller in the oldest version of the OS you need to support.

For example, to be sure of compatibility with "Snow Leopard" (10.6) and later versions, you should execute PyInstaller in that environment. You would create a copy of Mac OS X 10.6, typically in a virtual machine. In it, install the desired level of Python (the default Python in Snow Leopard was 2.6, which PyInstaller no longer supports), and install PyInstaller, your source, and all its dependencies. Then build your app in that environment. It should be compatible with later versions of Mac OS X.

Building 32-bit Apps in Mac OS X

Older versions of Mac OS X supported both 32-bit and 64-bit executables. PyInstaller builds an app using the the word-length of the Python used to execute it. That will typically be a 64-bit version of Python, resulting in a 64-bit executable. To create a 32-bit executable, run PyInstaller under a 32-bit Python.

Python as installed in OS X will usually be executable in either 64- or 32-bit mode. To verify this, apply the file command to the Python executable:

$ file /usr/local/bin/python3
/usr/local/bin/python3: Mach-O universal binary with 2 architectures
/usr/local/bin/python3 (for architecture i386):     Mach-O executable i386
/usr/local/bin/python3 (for architecture x86_64):   Mach-O 64-bit executable x86_64

The OS chooses which architecture to run, and typically defaults to 64-bit. You can force the use of either architecture by name using the arch command:

$ /usr/local/bin/python3
Python 3.4.2 (v3.4.2:ab2c023a9432, Oct  5 2014, 20:42:22)
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys; sys.maxsize

$ arch -i386 /usr/local/bin/python3
Python 3.4.2 (v3.4.2:ab2c023a9432, Oct  5 2014, 20:42:22)
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import sys; sys.maxsize

Apple's default /usr/bin/python may circumvent the arch specification and run 64-bit regardless. (That is not the case if you apply arch to a specific version such as /usr/bin/python2.7.) To make sure of running 32-bit in all cases, set the following environment variable:

arch -i386 /usr/bin/python pyinstaller --clean -F -w

Getting the Opened Document Names


Support for OpenDocument events is broken in PyInstaller 3.0 owing to code changes needed in the bootloader to support current versions of Mac OS X. Do not attempt to use this feature until it has been fixed. If this feature is important to you, follow and comment on the status of PyInstaller Issue #1309.

When a user double-clicks a document of a type your application supports, or when a user drags a document icon and drops it on your application's icon, Mac OS X launches your application and provides the name(s) of the opened document(s) in the form of an OpenDocument AppleEvent. This AppleEvent is received by the bootloader before your code has started executing.

The bootloader gets the names of opened documents from the OpenDocument event and encodes them into the argv string before starting your code. Thus your code can query sys.argv to get the names of documents that should be opened at startup.

OpenDocument is the only AppleEvent the bootloader handles. If you want to handle other events, or events that are delivered after the program has launched, you must set up the appropriate handlers.

Run-time Operation

Your app should run in a bundle exactly as it does when run from source. However, you might want to learn at run-time whether the app is running from source or "frozen" (bundled).

For example, you might have data files that, when running live, are found based on a module's __file__ attribute. That will not work when the code is bundled.

The PyInstaller bootloader adds the name frozen to the sys module. So the test for "are we bundled?" is:

import sys
if getattr( sys, 'frozen', False ) :
        # running in a bundle
else :
        # running live

Data files and folders of files can be included in the bundle. by editing the spec file; see Adding Files to the Bundle. The added files will be in the bundle folder.

The bootloader stores the absolute path to the bundle folder in sys._MEIPASS. For a one-folder bundle, this is the path to that folder, wherever the user may have put it. For a one-file bundle, this is the path to the _MEIxxxxxx temporary folder created by the bootloader (see How the One-File Program Works).

When your application needs access to a data file that is bundled with it, you get the path to the file with the following code:

import sys
import os
if getattr(sys, 'frozen', False):
    # we are running in a bundle
    basedir = sys._MEIPASS
    # we are running in a normal Python environment
    basedir = os.path.dirname(os.path.abspath(__file__))

This code sets basedir to the path to the folder containing your script and any other files or folders bundled with it. When your program was not started by the bootloader, the standard Python variable __file__ is the full path to the script now executing, and os.path.dirname() extracts the path to the folder that contains it. When bundled, sys._MEIPASS provides the path to bundle folder.

Using Spec Files

When you execute

pyinstaller options..

the first thing PyInstaller does is to build a spec (specification) file myscript.spec. That file is stored in the --specpath= directory, by default the current directory.

The spec file tells PyInstaller how to process your script. It encodes the script names and most of the options you give to the pyinstaller command. The spec file is actually executable Python code. PyInstaller builds the app by executing the contents of the spec file.

For many uses of PyInstaller you do not need to examine or modify the spec file. It is usually enough to give all the needed information (such as hidden imports) as options to the pyinstaller command and let it run.

There are four cases where it is useful to modify the spec file:

These uses are covered in topics below.

You create a spec file using this command:

pyi-makespec options [other scripts ...]

The options are the same options documented above for the pyinstaller command. This command creates the name.spec file but does not go on to build the executable.

After you have created a spec file and modified it as necessary, you build the application by passing the spec file to the pyinstaller command:

pyinstaller options name.spec

When you create a spec file, most command options are encoded in the spec file. When you build from a spec file, those options cannot be changed. If they are given on the command line they are ignored and replaced by the options in the spec file.

Only the following command-line options have an effect when building from a spec file:

Spec File Operation

After PyInstaller creates a spec file, or opens a spec file when one is given instead of a script, the pyinstaller command executes the spec file as code. Your bundled application is created by the execution of the spec file. The following is an shortened example of a spec file for a minimal, one-folder app:

block_cipher = None
a = Analysis([''],
pyz = PYZ(a.pure, a.zipped_data,
exe = EXE(pyz,... )
coll = COLLECT(...)

The statements in a spec file create instances of four classes, Analysis, PYZ, EXE and COLLECT.

  • A new instance of class Analysis takes a list of script names as input. It analyzes all imports and other dependencies. The resulting object (assigned to a) contains lists of dependencies in class members named:
    • scripts: the python scripts named on the command line;
    • pure: pure python modules needed by the scripts;
    • binaries: non-python modules needed by the scripts;
    • datas: non-binary files included in the app.
  • An instance of class PYZ is a .pyz archive (described under Inspecting Archives below), which contains all the Python modules from a.pure.
  • An instance of EXE is built from the analyzed scripts and the PYZ archive. This object creates the executable file.
  • An instance of COLLECT creates the output folder from all the other parts.

In one-file mode, there is no call to COLLECT, and the EXE instance receives all of the scripts, modules and binaries.

You modify the spec file to pass additional values to Analysis and to EXE.

Adding Files to the Bundle

To add files to the bundle, you create a list that describes the files and supply it to the Analysis call.

Adding Data Files

You provide a list that describes the files as the value of the datas= argument to Analysis. The list of data files is a list of tuples. Each tuple has two values, both of which must be strings:

  • The first string specifies the file or files as they are in this system now.
  • The second specifies the names of the files in the bundled app at run-time.

For example, to add a single README file to a one-folder app, you could modify the spec file as follows:

a = Analysis(...
     datas=[ ('src/README.txt', 'README') ],

You have made the datas= argument a one-item list. The item is a tuple in which the first string says the existing file is src/README.txt. This file will be copied into the bundle with name README.

The spec file is more readable if you create the list of added files in a separate statement:

added_files = [
     ( 'src/README.txt', 'README' )
a = Analysis(...
     datas= added_files,

The strings may use either / or \ as the path separator character. You can specify input files using "glob" abbreviations. When the input is multiple files, the output string may be the name of a folder. For example to include all the .mp3 files from a certain folder:

added_files = [
         ( '/mygame/sfx/*.mp3', 'sfx' ),
         ( 'src/README.txt', 'README' )

All files matching /mygame/sfx/*.mp3 will be copied into the bundle and stored in a folder named sfx.

The path to the input file or folder may be absolute as in the first tuple, or relative as in the second. When it is relative, it is taken as relative to the location of the spec file.

You can also include the entire contents of a folder:

added_files = [
         ( '/mygame/data', 'data' ),
         ( '/mygame/sfx/*.mp3', 'sfx' ),
         ( 'src/README.txt', 'README' )

All files in /mygame/data will be copied recursively into a folder named data in the bundle.

Adding Binary Files

To add binary files, make a list of tuples that describe the files needed. Assign the list of tuples to the binaries= argument of Analysis.

Normally PyInstaller learns about .so and .dll libraries by analyzing the imported modules. Sometimes it is not clear that a module is imported; in that case you use a --hidden-import= command option. But even that might not find all dependencies.

Suppose you have a module that is written in C and uses the Python C-API. Your program imports special_ops, and PyInstaller finds and includes But perhaps links to libiodbc.2.dylib. PyInstaller does not find this dependency. You could add it to the bundle this way:

a = Analysis(...
         binaries=[ ( '/usr/lib/libiodbc.2.dylib', 'libiodbc.dylib' ) ],

As with data files, if you have multiple binary files to add, create the list in a separate statement and pass the list by name.

Advanced Methods of Adding Files

PyInstaller supports a more advanced (and complex) way of adding files to the bundle that may be useful for special cases. See The TOC and Tree Classes below.

Giving Run-time Python Options

You can pass command-line options to the Python interpreter. The interpreter takes a number of command-line options but only the following are supported for a bundled app:

  • v to write a message to stdout each time a module is initialized.
  • u for unbuffered stdio.
  • W and an option to change warning behavior: W ignore or W once or W error.

To pass one or more of these options, create a list of tuples, one for each option, and pass the list as an additional argument to the EXE call. Each tuple has three elements:

  • The option as a string, for example v or W ignore.
  • None
  • The string OPTION

For example modify the spec file this way:

options = [ ('v', None, 'OPTION'), ('W ignore', None, 'OPTION') ]
a = Analysis( ...
exe = EXE(pyz,
      options,   <--- added line

Spec File Options for a Mac OS X Bundle

When you build a windowed Mac OS X app (that is, running in Mac OS X, you specify the --onefile --windowed options), the spec file contains an additional statement to create the Mac OS X application bundle, or app folder:

app = BUNDLE(exe,

The icon= argument to BUNDLE will have the path to an icon file that you specify using the --icon= option. The bundle_identifier will have the value you specify with the --osx-bundle-identifier= option.

An Info.plist file is an important part of a Mac OS X app bundle. (See the Apple bundle overview for a discussion of the contents of Info.plist.)

PyInstaller creates a minimal Info.plist. You can add or overwrite entries in the plist by passing an info_plist= parameter to the BUNDLE call. The value of this argument is a Python dict. Each key and value in the dict becomes a key and value in the Info.plist file. For example, when you use PyQt5, you can set NSHighResolutionCapable to True to let your app also work in retina screen:

app = BUNDLE(exe,
            'NSHighResolutionCapable': 'True'

The info_plist= parameter only handles simple key:value pairs. It cannot handle nested XML arrays. For example, if you want to modify Info.plist to tell Mac OS X what filetypes your app supports, you must add a CFBundleDocumentTypes entry to Info.plist (see Apple document types). The value of that keyword is a list of dicts, each containing up to five key:value pairs.

To add such a value to your app's Info.plist you must edit the plist file separately after PyInstaller has created the app. However, when you re-run PyInstaller, your changes will be wiped out. One solution is to prepare a complete Info.plist file and copy it into the app after creating it.

Begin by building and testing the windowed app. When it works, copy the Info.plist prepared by PyInstaller. This includes the CFBundleExecutable value as well as the icon path and bundle identifier if you supplied them. Edit the Info.plist as necessary to add more items and save it separately.

From that point on, to rebuild the app call PyInstaller in a shell script, and follow it with a statement such as:

cp -f Info.plist dist/

Multipackage Bundles


This feature is broken in the PyInstaller 3.0 release. Do not attempt building multipackage bundles until the feature is fixed. If this feature is important to you, follow and comment on PyInstaller Issue #1527.

Some products are made of several different apps, each of which might depend on a common set of third-party libraries, or share code in other ways. When packaging such an product it would be a pity to treat each app in isolation, bundling it with all its dependencies, because that means storing duplicate copies of code and libraries.

You can use the multipackage feature to bundle a set of executable apps so that they share single copies of libraries. You can do this with either one-file or one-folder apps. Each dependency (a DLL, for example) is packaged only once, in one of the apps. Any other apps in the set that depend on that DLL have an "external reference" to it, telling them to extract that dependency from the executable file of the app that contains it.

This saves disk space because each dependency is stored only once. However, to follow an external reference takes extra time when an app is starting up. All but one of the apps in the set will have slightly slower launch times.

The external references between binaries include hard-coded paths to the output directory, and cannot be rearranged. If you use one-folder mode, you must install all the application folders within a single parent directory. If you use one-file mode, you must place all the related applications in the same directory when you install the application.

To build such a set of apps you must code a custom spec file that contains a call to the MERGE function. This function takes a list of analyzed scripts, finds their common dependencies, and modifies the analyses to minimize the storage cost.

The order of the analysis objects in the argument list matters. The MERGE function packages each dependency into the first script from left to right that needs that dependency. A script that comes later in the list and needs the same file will have an external reference to the prior script in the list. You might sequence the scripts to place the most-used scripts first in the list.

A custom spec file for a multipackage bundle contains one call to the MERGE function:


MERGE is used after the analysis phase and before EXE and COLLECT. Its variable-length list of arguments consists of a list of tuples, each tuple having three elements:

  • The first element is an Analysis object, an instance of class Analysis, as applied to one of the apps.
  • The second element is the script name of the analyzed app (without the .py extension).
  • The third element is the name for the executable (usually the same as the script).

MERGE examines the Analysis objects to learn the dependencies of each script. It modifies these objects to avoid duplication of libraries and modules. As a result the packages generated will be connected.

Example MERGE spec file

One way to construct a spec file for a multipackage bundle is to first build a spec file for each app in the package. Suppose you have a product that comprises three apps named (because we have no imagination) foo, bar and zap:

pyi-makespec options as appropriate...

pyi-makespec options as appropriate...

pyi-makespec options as appropriate...

Check for warnings and test each of the apps individually. Deal with any hidden imports and other problems. When all three work correctly, combine the statements from the three files foo.spec, bar.spec and zap.spec as follows.

First copy the Analysis statements from each, changing them to give each Analysis object a unique name:

foo_a = Analysis([''],

bar_a = Analysis([''], etc., etc...

zap_a = Analysis([''], etc., etc...

Now call the MERGE method to process the three Analysis objects:

MERGE( (foo_a, 'foo', 'foo'), (bar_a, 'bar', 'bar'), (zap_a, 'zap', 'zap') )

The Analysis objects foo_a, bar_a, and zap_a are modified so that the latter two refer to the first for common dependencies.

Following this you can copy the PYZ, EXE and COLLECT statements from the original three spec files, substituting the unique names of the Analysis objects where the original spec files have a., for example:

foo_pyz = PYZ(foo_a.pure)
foo_exe = EXE(foo_pyz, foo_a.scripts, ... etc.
foo_coll = COLLECT( foo_exe, foo_a.binaries, foo_a.datas... etc.

bar_pyz = PYZ(bar_a.pure)
bar_exe = EXE(bar_pyz, bar_a.scripts, ... etc.
bar_coll = COLLECT( bar_exe, bar_a.binaries, bar_a.datas... etc.

(If you are building one-file apps, there is no COLLECT step.) Save the combined spec file as foobarzap.spec and then build it:

pyi-build foobarzap.spec

The output in the dist folder will be all three apps, but the apps dist/bar/bar and dist/zap/zap will refer to the contents of dist/foo/ for shared dependencies.

There are several multipackage examples in the PyInstaller distribution folder under /tests/old_suite/multipackage.

Remember that a spec file is executable Python. You can use all the Python facilities (for and with and the members of sys and io) in creating the Analysis objects and performing the PYZ, EXE and COLLECT statements. You may also need to know and use The TOC and Tree Classes described below.

When Things Go Wrong

The information above covers most normal uses of PyInstaller. However, the variations of Python and third-party libraries are endless and unpredictable. It may happen that when you attempt to bundle your app either PyInstaller itself, or your bundled app, terminates with a Python traceback. Then please consider the following actions in sequence, before asking for technical help.

Recipes and Examples for Specific Problems

The PyInstaller FAQ page has work-arounds for some common problems. Code examples for some advanced uses and some common problems are available on our PyInstaller Recipes page. Some of the recipes there include:

  • A more sophisticated way of collecting data files than the one shown above (Adding Files to the Bundle).
  • Bundling a typical Django app.
  • A use of a run-time hook to set the PyQt4 API level.
  • A workaround for a multiprocessing constraint under Windows.

and others. Many of these Recipes were contributed by users. Please feel free to contribute more recipes!

Finding out What Went Wrong

Build-time Messages

When the Analysis step runs, it produces error and warning messages. These display after the command line if the --log-level option allows it. Analysis also puts messages in a warnings file named build/name/warnname.txt in the work-path= directory.

Analysis creates a message when it detects an import and the module it names cannot be found. A message may also be produced when a class or function is declared in a package (an module), and the import specifies In this case, the analysis can't tell if name is supposed to refer to a submodule or package.

The "module not found" messages are not classed as errors because typically there are many of them. For example, many standard modules conditionally import modules for different platforms that may or may not be present.

All "module not found" messages are written to the build/name/warnname.txt file. They are not displayed to standard output because there are many of them. Examine the warning file; often there will be dozens of modules not found, but their absence has no effect.

When you run the bundled app and it terminates with an ImportError, that is the time to examine the warning file. Then see Helping PyInstaller Find Modules below for how to proceed.

Build-Time Python Errors

PyInstaller sometimes terminates by raising a Python exception. In most cases the reason is clear from the exception message, for example "Your system is not supported", or "Pyinstaller requires at least Python 2.7". Others clearly indicate a bug that should be reported.

One of these errors can be puzzling, however: IOError("Python library not found!") PyInstaller needs to bundle the Python library, which is the main part of the Python interpreter, linked as a dynamic load library. The name and location of this file varies depending on the platform in use. Some Python installations do not include a dynamic Python library by default (a static-linked one may be present but cannot be used). You may need to install a development package of some kind. Or, the library may exist but is not in a folder where PyInstaller is searching.

The places where PyInstaller looks for the python library are different in different operating systems, but /lib and /usr/lib are checked in most systems. If you cannot put the python library there, try setting the correct path in the environment variable LD_LIBRARY_PATH in Linux or DYLD_LIBRARY_PATH in OS X.

Getting Debug Messages

Giving the --debug option causes the bundled executable itself to write progress messages when it runs. This can be useful during development of a complex package, or when your app doesn't seem to be starting, or just to learn how the runtime works.

Normally the debug progress messages go to standard output. If the --windowed option is used when bundling a Windows app, they are displayed as MessageBoxes. For a --windowed Mac OS app they are not displayed.

Remember to bundle without --debug for your production version. Users would find the messages annoying.

Getting Python's Verbose Imports

You can also pass a -v (verbose imports) flag to the embedded Python interpreter (see Giving Run-time Python Options above). This can be extremely useful. It can be informative even with apps that are apparently working, to make sure that they are getting all imports from the bundle, and not leaking out to the local installed Python.

Python verbose and warning messages always go to standard output and are not visible when the --windowed option is used. Remember to not use this in the distributed program.

Helping PyInstaller Find Modules

Extending the Path

If Analysis recognizes that a module is needed, but cannot find that module, it is often because the script is manipulating sys.path. The easiest thing to do in this case is to use the --paths= option to list all the other places that the script might be searching for imports:

pyi-makespec --paths=/path/to/thisdir \

These paths will be noted in the spec file. They will be added to the current sys.path during analysis.

Listing Hidden Imports

If Analysis thinks it has found all the imports, but the app fails with an import error, the problem is a hidden import; that is, an import that is not visible to the analysis phase.

Hidden imports can occur when the code is using __import__ or perhaps exec or eval. Hidden imports can also occur when an extension module uses the Python/C API to do an import. When this occurs, Analysis can detect nothing. There will be no warnings, only an ImportError at run-time.

To find these hidden imports, build the app with the -v flag (Getting Python's Verbose Imports above) and run it.

Once you know what modules are needed, you add the needed modules to the bundle using the --hidden-import= command option, or by editing the spec file, or with a hook file (see Understanding PyInstaller Hooks below).

Extending a Package's __path__

Python allows a script to extend the search path used for imports through the __path__ mechanism. Normally, the __path__ of an imported module has only one entry, the directory in which the was found. But is free to extend its __path__ to include other directories. For example, the module actually resolves to win32com/win32comext/shell/shell.pyd. This is because win32com/ appends ../win32comext to its __path__.

Because the of an imported module is not actually executed during analysis, changes it makes to __path__ are not seen by PyInstaller. We fix the problem with the same hook mechanism we use for hidden imports, with some additional logic; see Understanding PyInstaller Hooks below.

Note that manipulations of __path__ hooked in this way apply only to the Analysis. At runtime all imports are intercepted and satisfied from within the bundle. is resolved the same way as win32com.anythingelse, and win32com.__path__ knows nothing of ../win32comext.

Once in a while, that's not enough.

Changing Runtime Behavior

More bizarre situations can be accomodated with runtime hooks. These are small scripts that manipulate the environment before your main script runs, effectively providing additional top-level code to your script.

There are two ways of providing runtime hooks. You can name them with the option --runtime-hook=path-to-script.

Second, some runtime hooks are provided. At the end of an analysis, the names in the module list produced by the Analysis phase are looked up in loader/rthooks.dat in the PyInstaller install folder. This text file is the string representation of a Python dictionary. The key is the module name, and the value is a list of hook-script pathnames. If there is a match, those scripts are included in the bundled app and will be called before your main script starts.

Hooks you name with the option are executed in the order given, and before any installed runtime hooks. If you specify then the execution order at runtime will be:

  1. Code of
  2. Code of
  3. Any hook specified for an included module that is found in rthooks/rthooks.dat.
  4. Your main script.

Hooks called in this way, while they need to be careful of what they import, are free to do almost anything. One reason to write a run-time hook is to override some functions or variables from some modules. A good example of this is the Django runtime hook (see loader/rthooks/ in the PyInstaller folder). Django imports some modules dynamically and it is looking for some .py files. However .py files are not available in the one-file bundle. We need to override the function in a way that will just return a list of values. The runtime hook does this as follows:

def _find_commands(_):
    return """cleanup shell runfcgi runserver""".split() = _find_commands

Getting the Latest Version

If you have some reason to think you have found a bug in PyInstaller you can try downloading the latest development version. This version might have fixes or features that are not yet at PyPI. You can download the latest stable version and the latest development version from the PyInstaller Downloads page.

If you have Git installed on your development system, you can use it together with pip to install the latest version of PyInstaller directly:

pip install -e git://

Asking for Help

When none of the above suggestions help, do ask for assistance on the PyInstaller Email List.

Then, if you think it likely that you see a bug in PyInstaller, refer to the How to Report Bugs page.

Advanced Topics

The following discussions cover details of PyInstaller internal methods. You should not need this level of detail for normal use, but such details are helpful if you want to investigate the PyInstaller code and possibly contribute to it, as described in How to Contribute.

The Bootstrap Process in Detail

There are many steps that must take place before the bundled script can begin execution. A summary of these steps was given in the Overview (How the One-Folder Program Works and How the One-File Program Works). Here is more detail to help you understand what the bootloader does and how to figure out problems.


The bootloader prepares everything for running Python code. It begins the setup and then returns itself in another process. This approach of using two processes allows a lot of flexibility and is used in all bundles except one-folder mode in Windows. So do not be surprised if you will see your bundled app as two processes in your system task manager.

What happens during execution of bootloader:

  1. First process: bootloader starts.

    1. If one-file mode, extract bundled files to temppath_MEIxxxxxx
    2. Set/unset various environment variables, e.g. override LD_LIBRARY_PATH on Linux or LIBPATH on AIX; unset DYLD_LIBRARY_PATH on OSX.
    3. Set up to handle signals for both processes.
    4. Run the child process.
    5. Wait for the child process to finish.
    6. If one-file mode, delete temppath_MEIxxxxxx.
  2. Second process: bootloader itself started as a child process.

    1. On Windows set the activation context.
    2. Load the Python dynamic library. The name of the dynamic library is embedded in the executable file.
    3. Initialize Python interpreter: set sys.path, sys.prefix, sys.executable.
    4. Run python code.

Running Python code requires several steps:

  1. Run the Python initialization code which prepares everything for running the user's main script. The initialization code can use only the Python built-in modules because the general import mechanism is not yet available. It sets up the Python import mechanism to load modules only from archives embedded in the executable. It also adds the attributes frozen and _MEIPASS to the sys built-in module.
  2. Execute any run-time hooks: first those specified by the user, then any standard ones.
  3. Install python "egg" files. When a module is part of a zip file (.egg), it has been bundled into the ./eggs directory. Installing means appending .egg file names to sys.path. Python automatically detects whether an item in sys.path is a zip file or a directory.
  4. Run the main script.

Python imports in a bundled app

PyInstaller embeds compiled python code (.pyc files) within the executable. PyInstaller injects its code into the normal Python import mechanism. Python allows this; the support is described in PEP 302 "New Import Hooks".

PyInstaller implements the PEP 302 specification for importing built-in modules, importing "frozen" modules (compiled python code bundled with the app) and for C-extensions. The code can be read in ./PyInstaller/loader/

At runtime the PyInstaller PEP 302 hooks are appended to the variable sys.meta_path. When trying to import modules the interpreter will first try PEP 302 hooks in sys.meta_path before searching in sys.path. As a result, the Python interpreter loads imported python modules from the archive embedded in the bundled executable.

This is the resolution order of import statements in a bundled app:

  1. Is it a built-in module? A list of built-in modules is in variable sys.builtin_module_names.
  2. Is it a module embedded in the executable? Then load it from embedded archive.
  3. Is it a C-extension? The app will try to find a file with name package.subpackage.module.pyd or
  4. Next examine paths in the sys.path. There could be any additional location with python modules or .egg filenames.
  5. If the module was not found then raise ImportError.

The TOC and Tree Classes

PyInstaller manages lists of files using the TOC (Table Of Contents) class. It provides the Tree class as a convenient way to build a TOC from a folder path.

TOC Class (Table of Contents)

Objects of the TOC class are used as input to the classes created in a spec file. For example, the scripts member of an Analysis object is a TOC containing a list of scripts. The pure member is a TOC with a list of modules, and so on.

Basically a TOC object contains a list of tuples of the form


In fact, it acts as an ordered set of tuples; that is, it contains no duplicates (where uniqueness is based on the name element of each tuple). Within this constraint, a TOC preserves the order of tuples added to it.

A TOC behaves like a list and supports the same methods such as appending, indexing, etc. A TOC also behaves like a set, and supports taking differences and intersections. In all of these operations a list of tuples can be used as one argument. For example, the following expressions are equivalent ways to add a file to the a.datas member:

a.datas.append( [ ('README', 'src/README.txt', 'DATA' ) ] )
a.datas += [ ('README', 'src/README.txt', 'DATA' ) ]

Set-difference makes excluding modules quite easy. For example:

a.binaries - [('badmodule', None, None)]

is an expression that produces a new TOC that is a copy of a.binaries from which any tuple named badmodule has been removed. The right-hand argument to the subtraction operator is a list that contains one tuple in which name is badmodule and the path and typecode elements are None. Because set membership is based on the name element of a tuple only, it is not necessary to give accurate path and typecode elements when subtracting.

In order to add files to a TOC, you need to know the typecode values and their related path values. A typecode is a one-word string. PyInstaller uses a number of typecode values internally, but for the normal case you need to know only three:

typecode description name path
'BINARY' A shared library. Run-time name. Full path name in build.
'DATA' Arbitrary files. Run-time name. Full path name in build.
'OPTION' A Python run-time option. Option code ignored.

The Tree Class

The Tree class is a way of creating a TOC that describes some or all of the files within a directory:

Tree(root, prefix=run-time-folder, excludes=match)
  • The root argument is a path string to a directory. It may be absolute or relative to the spec file directory.
  • The prefix argument, if given, is a name for a subfolder within the run-time folder to contain the tree files. If you omit prefix or give None, the tree files will be at the top level of the run-time folder.
  • The excludes argument, if given, is a list of one or more strings that match files in the root that should be omitted from the Tree. An item in the list can be either:
    • a name, which causes files or folders with this basename to be excluded
    • *.ext, which causes files with this extension to be excluded

For example:

extras_toc = Tree('../src/extras', prefix='extras', excludes=['tmp','*.pyc'])

This creates extras_toc as a TOC object that lists all files from the relative path ../src/extras, omitting those that have the basename (or are in a folder named) tmp or that have the type .pyc.

Each tuple in this TOC has:

  • A typecode of DATA,
  • A path consisting of a complete, absolute path to one file in the root folder,
  • A name consisting of the filename of this file, or, if you specify a prefix, the name is prefix/filename.

Inspecting Archives

An archive is a file that contains other files, for example a .tar file, a .jar file, or a .zip file. Two kinds of archives are used in PyInstaller. One is a ZlibArchive, which allows Python modules to be stored efficiently and, with some import hooks, imported directly. The other, a CArchive, is similar to a .zip file, a general way of packing up (and optionally compressing) arbitrary blobs of data. It gets its name from the fact that it can be manipulated easily from C as well as from Python. Both of these derive from a common base class, making it fairly easy to create new kinds of archives.


A ZlibArchive contains compressed .pyc or .pyo files. The PYZ class invocation in a spec file creates a ZlibArchive.

The table of contents in a ZlibArchive is a Python dictionary that associates a key, which is a member's name as given in an import statement, with a seek position and a length in the ZlibArchive. All parts of a ZlibArchive are stored in the marshalled format and so are platform-independent.

A ZlibArchive is used at run-time to import bundled python modules. Even with maximum compression this works faster than the normal import. Instead of searching sys.path, there's a lookup in the dictionary. There are no directory operations and no file to open (the file is already open). There's just a seek, a read and a decompress.

A Python error trace will point to the source file from which the archive entry was created (the __file__ attribute from the time the .pyc was compiled, captured and saved in the archive). This will not tell your user anything useful, but if they send you a Python error trace, you can make sense of it.



A CArchive can contain any kind of file. It's very much like a .zip file. They are easy to create in Python and easy to unpack from C code. A CArchive can be appended to another file, such as an ELF and COFF executable. To allow this, the archive is made with its table of contents at the end of the file, followed only by a cookie that tells where the table of contents starts and where the archive itself starts.

A CArchive can be embedded within another CArchive. An inner archive can be opened and used in place, without having to extract it.

Each table of contents entry has variable length. The first field in the entry gives the length of the entry. The last field is the name of the corresponding packed file. The name is null terminated. Compression is optional for each member.

There is also a type code associated with each member. The type codes are used by the self-extracting executables. If you're using a CArchive as a .zip file, you don't need to worry about the code.

The ELF executable format (Windows, Linux and some others) allows arbitrary data to be concatenated to the end of the executable without disturbing its functionality. For this reason, a CArchive's Table of Contents is at the end of the archive. The executable can open itself as a binary file, seek to the end and 'open' the CArchive.


Using pyi-archive_viewer

Use the pyi-archive_viewer command to inspect any type of archive:

pyi-archive_viewer archivefile

With this command you can examine the contents of any archive built with PyInstaller (a PYZ or PKG), or any executable (.exe file or an ELF or COFF binary). The archive can be navigated using these commands:

O name
Open the embedded archive name (will prompt if omitted). For example when looking in a one-file executable, you can open the outPYZ.pyz archive inside it.
Go up one level (back to viewing the containing archive).
X name
Extract name (will prompt if omitted). Prompts for an output filename. If none given, the member is extracted to stdout.

The pyi-archive_viewer command has these options:

-h, --help Show help.
-l, --log Quick contents log.
-b, --brief Print a python evaluable list of contents filenames.
-r, --recursive
 Used with -l or -b, applies recursive behaviour.

Inspecting Executables

You can inspect any executable file with pyi-bindepend:

pyi-bindepend executable_or_dynamic_library

The pyi-bindepend command analyzes the executable or DLL you name and writes to stdout all its binary dependencies. This is handy to find out which DLLs are required by an executable or by another DLL.

pyi-bindepend is used by PyInstaller to follow the chain of dependencies of binary extensions during Analysis.

Understanding PyInstaller Hooks

In summary, a "hook" file extends PyInstaller to adapt it to the special needs and methods used by a Python package. The word "hook" is used for two kinds of files. A runtime hook helps the bootloader to launch an app. For more on runtime hooks, see Changing Runtime Behavior. Other hooks run while an app is being analyzed. They help the Analysis phase find needed files.

The majority of Python packages use normal methods of importing their dependencies, and PyInstaller locates all their files without difficulty. But some packages make unusual uses of the Python import mechanism, or make clever changes to the import system at runtime. For this or other reasons, PyInstaller cannot reliably find all the needed files, or may include too many files. A hook can tell about additional source files or data files to import, or files not to import.

A hook file is a Python script, and can use all Python features. It can also import helper methods from PyInstaller.utils.hooks and useful variables from PyInstaller.compat. These helpers are documented below.

The name of a hook file is, where full-import-name is the fully-qualified name of an imported script or module. You can browse through the existing hooks in the hooks folder of the PyInstaller distribution folder and see the names of the packages for which hooks have been written. For example is a hook file telling about hidden imports needed by the module PyQt5.QtCore. When your script contains import PyQt5.QtCore (or from PyQt5 import QtCore), Analysis notes that exists, and will call it.

Many hooks consist of only one statement, an assignment to hiddenimports. For example, the hook for the dnspython package, called, has only this statement:

hiddenimports = [

When Analysis sees import dns.rdata or from dns import rdata it calls and examines its value of hiddenimports. As a result, it is as if your source script also contained:

import dns.rdtypes.*
import dsn.rdtypes.ANY.*

A hook can also cause the addition of data files, and it can cause certain files to not be imported. Examples of these actions are shown below.

When the module that needs these hidden imports is useful only to your project, store the hook file(s) somewhere near your source file. Then specify their location to the pyinstaller or pyi-makespec command with the --additional-hooks-dir= option. If the hook file(s) are at the same level as the script, the command could be simply:

pyinstaller --additional-hooks-dir=.

If you write a hook for a module used by others, please send us the hook file so we can make it available.

How a Hook Is Loaded

A hook is a module named in a folder where the Analysis object looks for hooks. Each time Analysis detects an import, it looks for a hook file with a matching name. When one is found, Analysis imports the hook's code into a Python namespace. This results in the execution of all top-level statements in the hook source, for example import statements, assignments to global names, and function definitions. The names defined by these statements are visible to Analysis as attributes of the namespace.

Thus a hook is a normal Python script and can use all normal Python facilities. For example it could test sys.version and adjust its assignment to hiddenimports based on that. There are over 150 hooks in the PyInstaller installation. You are welcome to browse through them for examples.

Hook Global Variables

A majority of the existing hooks consist entirely of assignments of values to one or more of the following global variables. If any of these are defined by the hook, Analysis takes their values and applies them to the bundle being created.


A list of module names (relative or absolute) that should be part of the bundled app. This has the same effect as the --hidden-import command line option, but it can contain a list of names and is applied automatically only when the hooked module is imported. Example:

hiddenimports = ['_proxy', 'utils', 'defs']

A list of module names (relative or absolute) that should not be part of the bundled app if they are only imported by the hooked module. (If they are explicitly imported by the source file, they will be kept.) Several hooks use this to prevent automatic inclusion of the tkinter module. Example:

excludedimports = ['matplotlib']

A list of files to bundle with the app as data. Each entry in the list is a tuple containing two strings. The first string specifies a file (or file "glob") in this system, and the second specifies the name(s) the file(s) are to have in the bundle. (This is the same format as used for the datas= argument, see Adding Data Files.) Example:

datas = [ ('/usr/share/icons/education_*.png', 'icons') ]

Many hooks use helpers from the PyInstaller.hooks.utils module (see below) to create this list, for example:

datas = collect_data_files('sphinx')

A list of files or directories to bundle as binaries. The format is the same as datas (tuples with strings that specify the source and the destination). Binaries is a special case of datas, in that PyInstaller will check each file to see if it depends on other dynamic libraries. Example:

binaries = [ ('C:\\Windows\\System32\\*.dll', 'dlls') ]

Many hooks use helpers from the PyInstaller.hooks.utils module to create this list (see below):

binaries = collect_dynamic_libs('zmq')

Useful Items in PyInstaller.compat

A hook may import the following names from PyInstaller.compat, for example:

from PyInstaller.compat import modname_tkinter, is_win
True when the active Python is version 2.7.
True when the active Python is version 3.X.
is_py34, is_py35, is_py36:
True in Python 3.4, 3.5 or 3.6 respectively.
True in a Windows system.
True when sys.platform=='cygwin'.
True in Mac OS X.
True in any Linux system (sys.platform.startswith('linux')).
True in Solaris.
True in AIX.
True in FreeBSD.
True in any virtual environment (either virtualenv or venv).
String, the correct path to the base Python installation, whether the installation is native or a virtual environment.

String, Tkinter in Python 2.7 but tkinter in Python 3. To prevent an unnecessary import of Tkinter, write:

from PyInstaller.compat import modname_tkinter
excludedimports = [ modname_tkinter ]
List of Python C-extension file suffixes. Used for finding all binary dependencies in a folder; see for an example.

Useful Items in PyInstaller.utils.hooks

A hook may import useful functions from PyInstaller.utils.hooks. Use a fully-qualified import statement, for example:

from PyInstaller.utils.hooks import collect_data_files, eval_statement

The PyInstaller.utils.hooks functions listed here are generally useful and used in a number of existing hooks. There are several more functions besides these that serve the needs of specific hooks, such as hooks for PyQt4/5. You are welcome to read the PyInstaller.utils.hooks module (and read the existing hooks that import from it) to get code and ideas.

exec_statement( statement ):

Execute a single Python statement in an externally-spawned interpreter and return the standard output that results, as a string. Examples:

tk_version = exec_statement(
   "from _tkinter import TK_VERSION; print(TK_VERSION)"

mpl_data_dir = exec_statement(
   "import matplotlib; print(matplotlib._get_data_path())"
datas = [ (mpl_data_dir, "") ]
eval_statement( statement ):

Execute a single Python statement in an externally-spawned interpreter. If the resulting standard output text is not empty, apply the eval() function to it; else return None. Example:

databases = eval_statement('''
   import sqlalchemy.databases
for db in databases:
   hiddenimports.append("sqlalchemy.databases." + db)
is_module_version( module, relation, version_string ):

Check the version of the named module (full-qualified) against a version string using the comparison operator relation. Example:

if is_module_version('sqlalchemy', '>=', '0.6') :

This function provides robust version checking based on the same low-level algorithm used by easy_install and pip, and should always be used in preference to writing your own comparison code. In particular, version strings should never be compared lexicographically (except for exact equality). For example '00.5' > '0.6' returns True, which is not correct.

The version_string is a PEP0440-compliant, dot-delimited version specifier such as 3.14-rc5. The relation is one of the following eight strings:

  • '>' or 'gt', greater-than.
  • '<' or 'lt', less-than.
  • '>=' or 'ge', greater-than-or-equal-to.
  • '<=' or 'le', less-than-or-equal-to.

collect_submodules( package, subdir=None, pattern=None ):

Returns a list of strings that specify all the modules in a package, ready to be assigned to the hiddenimports global. Returns an empty list when package does not name a package (a package is defined as a module that contains a __path__ attribute).

subdir, if given, names a relative subdirectory in the package, used in the case where a package imports modules at runtime from a directory lacking The pattern, if given, is a string that may be contained in the names of modules. Only modules containing the pattern will be returned. Example:

hiddenimports = collect_submodules( 'PIL', pattern='ImagePlugin' )
collect_data_files( module, subdir=None, include_py_files=False ):

Returns a list of (source, dest) tuples for all non-Python (i.e. data) files found in module, ready to be assigned to the datas global. module is a string giving the fully-qualified name of a module or package (but not a zipped "egg"). The function uses os.walk() to visit the module directory recursively. subdir, if given, restricts the search to a relative subdirectory.

Normally Python executable files (ending in .py, .pyc, etc.) are not collected. Pass include_py_files=True to collect those files as well. (This can be used with routines such as those in pkgutil that search a directory for Python executable files and load them as extensions or plugins.)

collect_dynamic_libs( module ):

Returns a list of (source, dest) tuples for all the dynamic libs present in a module directory. The list is ready to be assigned to the binaries global variable. The function uses os.walk() to examine all files in the module directory recursively. The name of each file found is tested against the likely patterns for a dynamic lib: *.dll, *.dylib, lib*.pyd, and lib*.so. Example:

binaries = collect_dynamic_libs( 'enchant' )
get_module_file_attribute( module ):

Return the absolute path to module, a fully-qualified module name. Example:

nacl_dir = os.path.dirname(get_module_file_attribute('nacl'))
get_package_paths( package ):

Given the name of a package, return a tuple. The first element is the absolute path to the folder where the package is stored. The second element is the absolute path to the named package. For example, if pkg.subpkg is stored in /abs/Python/lib the result of:

get_package_paths( 'pkg.subpkg' )

is the tuple, ( '/abs/Python/lib', '/abs/Python/lib/pkg/subpkg' )

get_homebrew_path( formula='' ):
Return the homebrew path to the named formula, or to the global prefix when formula is omitted. Returns None if not found.
Return the path to the top-level Python package containing the Django files, or None if nothing can be found.
django_dottedstring_imports( django_root_dir )
Return a list of all necessary Django modules specified in the Django file, such as the Django.settings.INSTALLED_APPS list and many others.

The hook(hook_api) Method

In addition to, or instead of, setting global values, a hook may define a function hook(hook_api). A hook() function should only be needed if the hook needs to apply sophisticated logic or to make a complex search of the source machine.

The Analysis object calls the function and passes it a hook_api object which has the following immutable properties:

The fully-qualified name of the module that caused the hook to be called, e.g., six.moves.tkinter.

The absolute path of the module. If it is:

  • A standard (rather than namespace) package, this is the absolute path of this package's directory.
  • A namespace (rather than standard) package, this is the abstract placeholder -.
  • A non-package module or C extension, this is the absolute path of the corresponding file.
A list of the absolute paths of all directories comprising the module if it is a package, or None. Typically the list contains only the absolute path of the package's directory.

The hook_api object also offers the following methods:

add_imports( names ):
The names argument may be a single string or a list of strings, giving the fully-qualified name(s) of modules to be imported. This has the same effect as adding the names to the hiddenimports global.
del_imports( names ):
The names argument may be a single string or a list of strings, giving the fully-qualified name(s) of modules that are not to be included if they are imported only by the hooked module. This has the same effect as adding names to the excludedimports global.
add_datas( tuple_list ):
The tuple_list argument has the format used with the datas global variable. This call has the effect of adding items to that list.
add_binaries( tuple_list ):
The tuple_list argument has the format used with the binaries global variable. This call has the effect of adding items to that list.

The hook() function can add, remove or change included files using the above methods of hook_api. Or, it can simply set values in the four global variables, because these will be examined after hook() returns.

The pre_find_module_path( pfmp_api ) Method

You may write a hook with the special function pre_find_module_path( pfmp_api ). This method is called when the hooked module name is first seen by Analysis, before it has located the path to that module or package (hence the name "pre-find-module-path").

Hooks of this type are only recognized if they are stored in a sub-folder named pre_find_module_path in a hooks folder, either in the distributed hooks folder or an --additional-hooks-dir folder. You may have normal hooks as well as hooks of this type for the same module. For example the distributed system has both a hooks/ and also a hooks/pre_find_module_path/

The pfmp_api object that is passed has the following immutable attribute:

A string, the fully-qualified name of the hooked module.

The pfmp_api object has one mutable attribute, search_dirs. This is a list of strings that specify the absolute path, or paths, that will be searched for the hooked module. The paths in the list will be searched in index sequence. The pre_find_module_path() function may replace or change the contents of pfmp_api.search_dirs.

Immediately after return from pre_find_module_path(), the contents of search_dirs will be used to find and analyze the module.

For an example of use, see the file hooks/pre_find_module_path/ It uses this method to redirect a search for distutils when PyInstaller is executing in a virtual environment.

The pre_safe_import_module( psim_api ) Method

You may write a hook with the special function pre_safe_import_module( psim_api ). This method is called after the hooked module has been found, but before it--and everything it recursively imports--is added to the "graph" of imported modules.

Hooks of this type are only recognized if they are stored in a sub-folder named pre_safe_import_module in a hooks folder, either in the distributed hooks folder or an --additional-hooks-dir folder. (See the distributed hooks/pre_safe_import_module folder for examples.)

You may have normal hooks as well as hooks of this type for the same module. For example the distributed system has both a hooks/ and also a hooks/pre_safe_import_module/

The psim_api object offers the following attributes, all of which are immutable (an attempt to change one raises an exception):

String, the unqualified name of the hooked module, for example text.
String, the fully-qualified name of the hooked module, for example email.mime.text.
The module graph representing all imports processed so far.
If this module is a top-level module of its package, None. Otherwise, the graph node that represents the import of the top-level module.

The last two items, module_graph and parent_package, are related to the module-graph, the internal data structure used by PyInstaller to document all imports. Normally you do not need to know about the module-graph.

The psim_api object also offers the following methods:

add_runtime_module( fully_qualified_name ):

Use this method to add an imported module whose name may not appear in the source because it is dynamically defined at run-time. A typical use applies the name from the psim_api:

psim_api.add_runtime_module( psim_api.module_name )
add_alias_module( real_module_name, alias_module_name ):
real_module_name is the fully-qualifed name of an existing module, one that has been or could be imported by name (it will be added to the graph if it has not already been imported). alias_module_name is a name that might be referenced in the source file but should be treated as if it were real_module_name. This method ensures that if PyInstaller processes an import of alias_module_name it will use real_module_name.
append_package_path( directory ):
The hook can use this method to add a package path to be searched by PyInstaller, typically an import path that the imported module would add dynamically to the path if the module was executed normally. directory is a string, a pathname to add to the __path__ attribute.

Building the Bootloader

PyInstaller comes with binary bootloaders for most platforms in the bootloader folder of the distribution folder. For most cases, these precompiled bootloaders are all you need.

If there is no precompiled bootloader for your platform, or if you want to modify the bootloader source, you need to build the bootloader.


This will produce the bootloader executables,

Note: If you have multiple versions of Python, the Python you use to run waf is the one whose configuration is used.

If this reports an error, read the detailed notes that follow, then ask for technical help.

Development tools

On Debian/Ubuntu systems, you can run the following to install everything required:

sudo apt-get install build-essential

On Fedora/RHEL and derivates, you can run the following:

yum groupinstall "Development Tools"

On Mac OS X you can get gcc by installing Xcode. It is a suite of tools for developing software for Mac OS X. It can be also installed from your Mac OS X Install DVD. It is not necessary to install the version 4 of Xcode.

On Solaris and AIX the bootloader is built and tested with gcc.

Building for Windows

On Windows you can use the Visual Studio C++ compiler (Visual Studio 2008 is recommended). A free version you can download is Visual Studio Express.

Note: When compiling libs to link with Python it is important to use the same level of Visual Studio as was used to compile Python. That is not the case here. The bootloader is a self-contained static executable that imposes no restrictions on the version of Python being used. So you can use any Visual Studio version that is convenient.

If Visual Studio is not convenient, you can download and install the MinGW distribution from one of the following locations:

  • MinGW-w64 required, uses gcc 4.4 and up.
  • TDM-GCC - MinGW (not used) and MinGW-w64 installers

On Windows, when using MinGW-w64, add PATH_TO_MINGW\bin to your system PATH. variable. Before building the bootloader run for example:

set PATH=C:\MinGW\bin;%PATH%

Change to the bootloader subdirectory. Run:

python ./waf distclean all

This will produce the bootloader executables run*.exe in the .\PyInstaller\bootloader\YOUR_OS directory.

Building for LINUX

By default, the bootloaders on Linux are LSB binaries.

LSB is a set of open standards that should increase compatibility among Linux distributions. PyInstaller produces a bootloader as an LSB binary in order to increase compatibility for packaged applications among distributions.

Note: LSB version 4.0 is required for successfull building of bootloader.

On Debian- and Ubuntu-based distros, you can install LSB 4.0 tools by adding the following repository to the sources.list file:

deb lsb-4.0 main

then after having update the apt repository:

sudo apt-get update

you can install LSB 4.0:

sudo apt-get install lsb lsb-build-cc

Most other distributions contain only LSB 3.0 in their software repositories and thus LSB build tools 4.0 must be downloaded by hand. From Linux Foundation download LSB sdk 4.0 for your architecture.

Unpack it by:

tar -xvzf lsb-sdk-4.0.3-1.ia32.tar.gz

To install it run:

cd lsb-sdk

After having installed the LSB tools, you can follow the standard building instructions.

NOTE: if for some reason you want to avoid LSB compilation, you can do so by specifying --no-lsb on the waf command line, as follows:

python waf configure --no-lsb build install

This will also produce support/loader/YOUR_OS/run, support/loader/YOUR_OS/run_d, support/loader/YOUR_OS/runw and support/loader/YOUR_OS/runw_d, but they will not be LSB binaries.