Re: [gentoo-science] Strange scipy-0.12.0 dependencies

Quoting Jan Marten Simons <marten@××××××××××××××××.de>:

> Hi sci,
>
> While trying to update my installation I got a rather strange result, which I
> cannot really make any sense of:
>
> # emerge -avt scipy
>
> These are the packages that would be merged, in reverse order:
>
> Calculating dependencies... done!
>
> emerge: there are no ebuilds built with USE flags to satisfy "virtual/python-
> imaging[python_targets_python2_5(-)?,python_targets_python2_6(-)?,python_targets_python2_7(-)?,python_targets_python3_2(-)?,python_targets_python3_3(-)?,-
> python_single_target_python2_5(-),-python_single_target_python2_6(-),-
> python_single_target_python2_7(-),-python_single_target_python3_2(-),-
> python_single_target_python3_3(-)]".
> !!! One of the following packages is required to complete your request:
> - sci-libs/scipy-0.12.0::gentoo (Change USE: -python_targets_python3_2 -
> python_targets_python2_7, this change violates use flag constraints
> defined by
> sci-libs/scipy-0.12.0: 'any-of ( python_targets_python2_5
> python_targets_python2_6 python_targets_python2_7 python_targets_python3_2
> python_targets_python3_3 )')
> (dependency required by "sci-libs/scipy-0.12.0" [ebuild])
> (dependency required by "scipy" [argument])
>
> I wonder what might be wrong here. Any idea on this?
>
I have just hit that and need to fix things in the sage-on-gentoo overlay.
This is caused by a combination of things:
1) scipy now supports python3 target
2) migration to virtual/python-imaging

By default portage will now want to build scipy for python 3.2. But you 
probably
still use imaging which python 2.x only rather than the fork pillow which is
compatible with python 3.x.

pillow and imaging cannot be installed at the same time (they are mutual
blockers). Because you have an historic imaging install virtual/python-imaging
default to python 2.x targets and no python 3.x targets.

Solutions:
1) restrict scipy to python 2.7 in package.use
or
2) migrate to pillow

Francois