Merge topic 'allow-optional-python-linking' fails in Windows.

(Andrew Maclean) #1

@ben.boeckel, this merge causes a build failure wrt Python wrapping in Windows.

It seems the linker is unable to find the Python library:

LINK : fatal error LNK1104: cannot open file 'python37.lib'

I can get a build if I set VTK_PYTHON_OPTIONAL_LINK to OFF.

This popped up a while back in VTK_PYTHON_OPTIONAL_LINK

(Ben Boeckel) #2

Hmm. Our Windows Python builders are OK with it. That line seems to indicate that there is autolinking going on somewhere. Maybe this is new in 3.6? I think we only test up to 3.5 now and Windows is a 3.5 tester.

(Ben Boeckel) #3

Hrm, yep, I see autolinking in pyconfig.h. There’s no way to disable it either :confused: . Seems we have to disable its addition either :frowning: . Though it isn’t new in 3.6 either. So I guess the question is: why is it working on mun?

(Andrew Maclean) #4

@ben.boeckel I hope you find out what’s happening on mun! I spent a lot of time trying many things, including deleting everything and rebuilding, and I was even considering reverting to an older version of Visual Studio as a last resort. However when I was writing this post, Discourse picked up the older post I referred to. So I was able to build based on the comments in that! So Discourse works!
One other thing is that I am using Anaconda Python, but that shouldn’t matter.

(Ben Boeckel) #5

Well, Anaconda (frustratingly) tends to build their Python versions differently than binaries (which is what we’re using). @danlipsa did you encounter any Windows issues with the Anaconda VTK you were working on?

(Dan Lipsa) #6

I have not tested on windows. We don’t use Windows packages but rather Unix packages under the Windows’s Unix subsystem.

(Jean Christophe Fillion Robin (Kitware)) #7

On windows, it is indeed required to link against the python library, there are no use of weak linking and the python shared library is always distributed 1, 2

1 This is always true when dealing with a CPython distribution able to load python modules.
2 In the case of statically built CPython distribution, no shared library would be available but that is an unrelated usecase

(Ben Boeckel) #8

OK, so we should then add NOT WIN32 to that conditional then.