Is it possible to specify variant as part of depends_lib?

[Mojca Miklavec]

On 19 April 2018 at 10:24, Chris Jones  wrote:
> On 18/04/18 18:39, Edward Maros wrote:
>>
>> I have a package (gds) that has a build requirement on port root5 with
>> the variant +python27.
>>
>> Currently the buildbot system will not build the gds package because it
>> installs the root5 package with only default variants.
>
> Do you *really* mean root5 ? port info says it requires root6
>
> Titan ~ > port info gds
> gds @2.18.7 (science)
> Variants:             universal
>
> Description:          LIGO Scientific Collaboration Algorithm Library
> containing core routines for gravitational wave data analysis.
> Homepage: https://www.lsc-group.phys.uwm.edu/daswg/projects/lalsuite.html
>
> Build Dependencies:   pkgconfig, swig, swig-python
> Library Dependencies: python27, py27-numpy, curl, expat, fftw-3,
> fftw-3-single, hdf5, jsoncpp, ldas-tools-framecpp, metaio, root6
> Platforms:            darwin
> License:              GPL
> Maintainers:          Email: ed.maros at ligo.org, GitHub: emaros
>                       Policy: openmaintainer
>
> I did indeed recently change the default python variant of root6 to be
> python36, from python27, just to be ready for the time python 2.7 is
> officially depreciated. I don't really think going back to python27 makes
> sense, so I would suggest going forward you should look to making python36
> the default for gds as well.

I didn't check this particular port. It could be that the rest of the
code in this software would not be compatible with python 3, but
that's pure speculation.

In any case, it would be really nice if we could provide root6 and
pyXY-root6 as separate standalone ports, so that users could then
easily switch to a different version of Python if needed. But that's
something where it would help a lot if upstream was willing to modify
the build system in such a way that one would not need to recompile
the complete clang & ROOT just for the sake of compiling and
installing a couple of python support files.

Edward, if you are willing to push upstream to make the change to
simplify packaging of python code separately ...

Mojca