ImportError: libgfortran.so.4 with conda Sherpa 4.10

In Gammapy we have a build that now fetches Sherpa 4.10 and fails like this: https://travis-ci.org/gammapy/gammapy/jobs/377744827#L3797

$ python -c 'import sherpa.optmethods'
...
/home/travis/miniconda/envs/test/lib/python2.7/site-packages/sherpa-4.10.0-py2.7-linux-x86_64.egg/sherpa/optmethods/optfcts.py:29: ImportError
ImportError: libgfortran.so.4: cannot open shared object file: No such file or directory
...

I think basically we do the equivalent of this in our .travis.yml, but I’m not sure:

conda channel --add conda-forge sherpa
conda install sherpa libgfortran

This build used to work with Sherpa 4.9, so presumably something changed in 4.10? Or is our .travis.yml no good and we fetch e.g. a wrong libgfortran for some reason? @olaurino - Help?

PS: locally on Mac with Sherpa 4.10 from conda all Gammapy tests pass.

[cdeil]

This install issue was resolved via the latest Sherpa release: https://github.com/sherpa/sherpa/releases/tag/4.10.1

They removed the Fortran dependency in https://github.com/sherpa/sherpa/pull/481 (we don’t use xspec in Gammapy).

This build from a few days ago is with Sherpa 4.10.0 and has the libgfortran link error: https://travis-ci.org/gammapy/gammapy/jobs/440784483#L2483

This build is from today with Sherpa 4.10.1 and passed without error: https://travis-ci.org/gammapy/gammapy/jobs/442767281#L2477

@olaurino - Thanks! 🚀🥇 🍕 🍻

[bsipocz]

@cdeil - I’m sorry, this ping has lost in the weeds of my move. Next time try to ping me elsewhere, too if there is no initial response.