auditwheel 1.1.0

Overview

auditwheel is a command line tool to facilitate the creation of Python wheel packages for Linux containing pre-compiled binary extensions are compatible with a wide variety of Linux distributions, consistent with the PEP 513 manylinux1 platform tag.

auditwheel show: shows external shared libraries that the wheel depends on (beyond the libraries included in the manylinux1 policy), and checks the extension modules for the use of versioned symbols that exceed the manylinux_ ABI.

auditwheel repair: copies these external shared libraries into the wheel itself, and automatically modifies the appropriate RPATH entries such that these libraries will be picked up at runtime. This accomplishes a similar result as if the libraries had been statically linked without requiring changes to the build system. Packagers are advised that bundling, like static linking, may implicate copyright concerns.

Installation

auditwheel can be installed using pip:

pip3 install auditwheel

It requires Python 3.3+, and runs on Linux. It requires that the shell command unzip be available in the PATH. Only systems that use ELF-based linkage are supported (this should be essentially every Linux).

But in general, building manylinux1 wheels requires running on a CentOS5 machine, so we recommend using the pre-built manylinux Docker image.

$ docker run -i -t -v `pwd`:/io quay.io/manylinux/manylinux /bin/bash

Examples

Inspecting a wheel:

$ auditwheel show cffi-1.5.0-cp35-cp35m-linux_x86_64.whl

  cffi-1.5.0-cp35-cp35m-linux_x86_64.whl is consistent with the
  following platform tag: "linux_x86_64".

  The wheel references the following external versioned symbols in
  system-provided shared libraries: GLIBC_2.3.

  The following external shared libraries are required by the wheel:
  {
      "libc.so.6": "/lib64/libc-2.5.so",
      "libffi.so.5": "/usr/lib64/libffi.so.5.0.6",
      "libpthread.so.0": "/lib64/libpthread-2.5.so"
  }

  In order to achieve the tag platform tag "manylinux1_x86_64" the
  following shared library dependencies will need to be eliminated:

  libffi.so.5

Repairing a wheel.

$ auditwheel repair cffi-1.5.0-cp35-cp35m-linux_x86_64.whl
Repairing cffi-1.5.0-cp35-cp35m-linux_x86_64.whl
Grafting: /usr/lib64/libffi.so.5.0.6
Setting RPATH: _cffi_backend.cpython-35m-x86_64-linux-gnu.so

Writing fixed-up wheel written to wheelhouse/cffi-1.5.0-cp35-cp35m-linux_x86_64.whl

Limitations

1. auditwheel uses the DT_NEEDED information (like ldd) from the Python extension modules to determine which system system libraries they depend on. Code that that dynamically loads libraries at at runtime using ctypes / cffi (from Python) or dlopen (from C/C++) doesn’t contain this information in a way that can be statically determined, so dependencies that are loaded via those mechanisms will be missed.

2. There’s nothing we can do about “fixing” binaries if they were compiled and linked against a too-recent version of libc ot libstdc++. These libraries (and some others) use symbol versioning for backward compatibility. In general, this means that code that was compiled against an old version of glibc will run fine on systems with a newer version of glibc, but code what was compiled on a new system won’t / might not run on older system.

   So, to compile widely-compatible binaries, you’re best off doing the build on an old Linux distribution, such as the manylinux Docker image.