[vtk-developers] Fwd: OSX build links directly with Python binary - avoidable?

[Matthew Brett]

Hi,

I have spent a little time trying to build OSX wheels [1] for VTK.
These would be very useful for an automated binary install of VTK for
OSX Python.

Short version : vtk python libraries link directly against the Python
binary, making more general packaging impossible.

Long version:

My plan was to first do an install into the Python site-packages, copy
and do a relative path relink of the library dependencies into a
`.dylibs` directory [2] and then package the files into a wheel.

My first shot was using the homebrew installation:

brew install vtk --with-python --with-qt --with-matplotlib

This installation can't be used with a Python other than the one it is
compiled with, because it links directly to the Python binary.  The
output from this:

cd /usr/local/Cellar/vtk/6.2.0/lib/python2.7/site-packages/vtk
otool -L vtkCommonCorePython.so

includes:

/usr/local/opt/python/Frameworks/Python.framework/Versions/2.7/Python
(compatibility version 2.7.0, current version 2.7.0)

This is true for many (?all) other vtk compiled extension modules.

Is there any reason that this library has to link directly the Python
binary?  It makes it impossible to make a package that will install
for a Python other than the one it was built with, and at the same
path.

I believe standard practice is to use " -undefined dynamic_lookup "
for Python symbols loaded from extension modules, but I am happy to be
corrected.

Cheers,

Matthew

[1] https://github.com/MacPython/wiki/wiki/Spinning-wheels
[2] https://github.com/matthew-brett/delocate