macOS utilities to:
- find dynamic libraries imported from python extensions
- copy needed dynamic libraries to directory within package
- update macOS
rpathto cause code to load from copies of libraries
delocate-listdeps-- show libraries a tree depends on
delocate-path-- copy libraries a tree depends on into the tree and relink
delocate-wheel-- rewrite wheel having copied and relinked library dependencies into the wheel tree.
Auditwheel is a similar tool for Linux. Auditwheel started life as a partial fork of Delocate.
Let's say you have built a wheel somewhere, but it's linking to dynamic libraries elsewhere on the machine, so you can't distribute it, because others may not have these same libraries. Here we analyze the dependencies for a Scipy wheel:
$ delocate-listdeps scipy-0.14.0b1-cp34-cp34m-macosx_10_6_intel.whl /usr/local/Cellar/gfortran/4.8.2/gfortran/lib/libgcc_s.1.dylib /usr/local/Cellar/gfortran/4.8.2/gfortran/lib/libgfortran.3.dylib /usr/local/Cellar/gfortran/4.8.2/gfortran/lib/libquadmath.0.dylib
By default, this does not include libraries in
See those too with:
$ delocate-listdeps --all scipy-0.14.0-cp34-cp34m-macosx_10_6_intel.whl /System/Library/Frameworks/Accelerate.framework/Versions/A/Accelerate /usr/lib/libSystem.B.dylib /usr/lib/libstdc++.6.dylib /usr/local/Cellar/gfortran/4.8.2/gfortran/lib/libgcc_s.1.dylib /usr/local/Cellar/gfortran/4.8.2/gfortran/lib/libgfortran.3.dylib /usr/local/Cellar/gfortran/4.8.2/gfortran/lib/libquadmath.0.dylib
The output tells me that Scipy has picked up dynamic libraries from my
Homebrew installation of
gfortran (as well as the system libs).
You can get a listing of the files depending on each of the libraries,
$ delocate-listdeps --depending scipy-0.14.0-cp34-cp34m-macosx_10_6_intel.whl /usr/local/Cellar/gfortran/4.8.2/gfortran/lib/libgcc_s.1.dylib: scipy/interpolate/dfitpack.so scipy/special/specfun.so scipy/interpolate/_fitpack.so ...
We can fix like this:
$ delocate-wheel -w fixed_wheels -v scipy-0.14.0-cp34-cp34m-macosx_10_6_intel.whl Fixing: scipy-0.14.0-cp34-cp34m-macosx_10_6_intel.whl Copied to package .dylibs directory: /usr/local/Cellar/gfortran/4.8.2/gfortran/lib/libgcc_s.1.dylib /usr/local/Cellar/gfortran/4.8.2/gfortran/lib/libgfortran.3.dylib /usr/local/Cellar/gfortran/4.8.2/gfortran/lib/libquadmath.0.dylib
-w flag tells delocate-wheel to output to a new wheel directory
instead of overwriting the old wheel.
-v (verbose) tells you what
delocate-wheel is doing. In this case it has made a new directory in the
wheel zipfile, named
scipy/.dylibs. It has copied all the library
dependencies that are outside the macOS system trees into this directory, and
patched the python
.so extensions in the wheel to use these copies instead
of looking in
Check the links again to confirm:
$ delocate-listdeps --all fixed_wheels/scipy-0.14.0-cp34-cp34m-macosx_10_6_intel.whl /System/Library/Frameworks/Accelerate.framework/Versions/A/Accelerate /usr/lib/libSystem.B.dylib /usr/lib/libstdc++.6.0.9.dylib @loader_path/../../../../.dylibs/libgcc_s.1.dylib @loader_path/../../../../.dylibs/libgfortran.3.dylib @loader_path/../../../../.dylibs/libquadmath.0.dylib @loader_path/../../../.dylibs/libgcc_s.1.dylib @loader_path/../../../.dylibs/libgfortran.3.dylib @loader_path/../../../.dylibs/libquadmath.0.dylib @loader_path/../../.dylibs/libgcc_s.1.dylib @loader_path/../../.dylibs/libgfortran.3.dylib @loader_path/../../.dylibs/libquadmath.0.dylib @loader_path/../.dylibs/libgcc_s.1.dylib @loader_path/../.dylibs/libgfortran.3.dylib @loader_path/../.dylibs/libquadmath.0.dylib @loader_path/libgcc_s.1.dylib @loader_path/libquadmath.0.dylib
So - system dylibs the same, but the others moved into the wheel tree.
This makes the wheel more likely to work on another machine which does not have the same version of Gfortran installed - in this example.
Checking required architectures
Current Python.org Python and the macOS system Python (
are both dual architecture binaries. For example:
$ lipo -info /usr/bin/python Architectures in the fat file: /usr/bin/python are: x86_64 arm64e
This Big Sur macOS Python has both
arm64 (M1) versions
fused into one file. Earlier versions of macOS had dual architectures that
were 32-bit (
i386) and 64-bit (
For full compatibility with system and Python.org Python, wheels built for
Python.org Python or system Python should have the corresponding architectures
arm64 versions of the Python extensions and their
libraries. It is easy to link Python extensions against single architecture
libraries by mistake, and therefore get single architecture extensions and /
or libraries. In fact my Scipy wheel is one such example, because I
inadvertently linked against the Homebrew libraries, which were
only. To check this you can use the
$ delocate-wheel --require-archs=intel scipy-0.14.0-cp34-cp34m-macosx_10_6_intel.whl Traceback (most recent call last): File "/Users/mb312/.virtualenvs/delocate/bin/delocate-wheel", line 77, in <module> main() File "/Users/mb312/.virtualenvs/delocate/bin/delocate-wheel", line 69, in main check_verbose=opts.verbose) File "/Users/mb312/.virtualenvs/delocate/lib/python2.7/site-packages/delocate/delocating.py", line 477, in delocate_wheel "Some missing architectures in wheel") delocate.delocating.DelocationError: Some missing architectures in wheel
Notice that this command was using an earlier version of Delocate that supported Python 2; we now support Python 3 only.
intel argument to
--require-arch above requires dual 32- and 64-
bit architecture extensions and libraries. You can see which extensions are at
fault by adding the
-v (verbose) flag:
$ delocate-wheel -w fixed_wheels --require-archs=intel -v scipy-0.14.0-cp34-cp34m-macosx_10_6_intel.whl Fixing: scipy-0.14.0-cp34-cp34m-macosx_10_6_intel.whl Required arch i386 missing from /usr/local/Cellar/gfortran/4.8.2/gfortran/lib/libgfortran.3.dylib Required arch i386 missing from /usr/local/Cellar/gfortran/4.8.2/gfortran/lib/libquadmath.0.dylib Required arch i386 missing from scipy/fftpack/_fftpack.so Required arch i386 missing from scipy/fftpack/convolve.so Required arch i386 missing from scipy/integrate/_dop.so ...
I need to rebuild this wheel to link with dual-architecture libraries.
DelocationError: "library does not exist"
delocate-wheel or its sister command
may get errors like this:
delocate.delocating.DelocationError: library "<long temporary path>/wheel/libme.dylib" does not exist
This happens when one of your libraries gives a library dependency with a
relative path. For example, let's say that some file in my wheel has this for
the output of
otool -L myext.so:
myext.so: libme.dylib (compatibility version 10.0.0, current version 10.0.0) /usr/lib/libstdc++.6.dylib (compatibility version 7.0.0, current version 60.0.0) /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1197.1.1)
The first line means that
myext.so expects to find
exactly the path
./libme.dylib - the current working directory from which
you ran the executable. The output should be something like:
myext.so: /path/to/libme.dylib (compatibility version 10.0.0, current version 10.0.0) /usr/lib/libstdc++.6.dylib (compatibility version 7.0.0, current version 60.0.0) /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1197.1.1)
To set the path to the library, the linker is using the install name id of
the linked library. In this bad case, then
otool -L libme.dylib will give
libme.dylib (compatibility version 10.0.0, current version 10.0.0) /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1197.1.1)
where the first line is the install name id that the linker picked up when
libme.dylib. You job is to fix the build process
libme.dylib has install name id
This is not a problem specific to Delocate; you will need to do this to
make sure that
myext.so can load
being in the current working directory. For
CMAKE builds you may want to
check out CMAKE_INSTALL_NAME_DIR.
Released under the BSD two-clause license - see the file
LICENSE in the
travis-ci kindly tests the code automatically under Python 3.6 through 3.9.
The latest released version is at https://pypi.python.org/pypi/delocate
Please put up issues on the Delocate issue tracker.