mac gfortran needs and cannot find cc1

[minrk]

CMake runs:

$FC --help -v

to determine certain flag support (-isysroot came up in conda-forge/netcdf-fortran-feedstock#28). However, running this with the conda gfortran on mac fails with:

cc1 -quiet -v ...
x86_64-apple-darwin13.4.0-gfortran: error trying to exec 'cc1': execvp: No such file or directory

causing cmake to misconfigure the gfortran compiler (omitting -isysroot in the above case).

Googling around suggests that this command should succeed, which it does on linux:

$ x86_64-conda_cos6-linux-gnu-gcc -print-prog-name=cc1
/opt/conda/bin/../libexec/gcc/x86_64-conda_cos6-linux-gnu/7.3.0/cc1

but on mac, it doesn't find cc1:

$ x86_64-apple-darwin13.4.0-gfortran -print-prog-name=cc1
cc1

I'm not sure if there's a missing file, dependency, patch, or environment variable needed for finding cc1, but something appears to be missing.

[minrk]

seems like maybe gfortran_osx-64 should depend on gcc_osx-64 (or impl), but gcc doesn't appear to be packaged for mac.

[mingwandroid]

Yeah, probably.

PRs welcome, gfortran is basically the same on conda-forge as it is on defaults. If you make a PR there then I will rebase on top of that.

Otherwise you'll need to add {{ compiler('c') }} as a work-around.

Cheers!

[jaimergp]

Hey @minrk, did you get to solve this problem? I am seeing this exact situation in conda-forge/ambertools-feedstock#16 for MacOS, even with the C compiler in the requirements. Any suggestions or workarounds? Thanks!

[minrk]

The workaround for netcdf was to explicitly add sysroot:

if [[ $(uname) == Darwin ]]; then
  export FFLAGS="-isysroot $CONDA_BUILD_SYSROOT $FFLAGS"
fi

[jaimergp]

Thanks for your answer! Yes, I have that line present too, but doesn't seem to have much on an effect :/

I guess there's something wrong with the upstream package itself.

Thanks again for your help!