fpm fails to build on macOS with Conda

[certik]

I use the usual conda create -n fpm fpm gfortran clang and then go to the fpm git repository and:

$ fpm build
 + mkdir -p build/dependencies
Initialized empty Git repository in /Users/certik/repos/fortran-lang/fpm/build/dependencies/toml-f/.git/
remote: Enumerating objects: 115, done.
remote: Counting objects: 100% (115/115), done.
remote: Compressing objects: 100% (104/104), done.
remote: Total 115 (delta 27), reused 47 (delta 8), pack-reused 0
Receiving objects: 100% (115/115), 105.17 KiB | 158.00 KiB/s, done.
Resolving deltas: 100% (27/27), done.
From https://github.com/toml-f/toml-f
 * branch            2f5eaba864ff630ba0c3791126a3f811b6e437f3 -> FETCH_HEAD
Initialized empty Git repository in /Users/certik/repos/fortran-lang/fpm/build/dependencies/M_CLI2/.git/
remote: Enumerating objects: 191, done.
remote: Counting objects: 100% (191/191), done.
remote: Compressing objects: 100% (110/110), done.
remote: Total 191 (delta 93), reused 156 (delta 80), pack-reused 0
Receiving objects: 100% (191/191), 1.08 MiB | 166.00 KiB/s, done.
Resolving deltas: 100% (93/93), done.
From https://github.com/urbanjost/M_CLI2
 * branch            ea6bbffc1c2fb0885e994d37ccf0029c99b19f24 -> FETCH_HEAD
 + mkdir -p build/gfortran_2A42023B310FA28D/fpm
 + gfortran -c ././src/filesystem_utilities.c -o build/gfortran_2A42023B310FA28D/fpm/src_filesystem_utilities.c.o
gfortran: fatal error: cannot execute ‘cc1’: execvp: No such file or directory
compilation terminated.
 <ERROR> Compilation failed for object "src_filesystem_utilities.c.o"
STOP 1

The failure comes from the fact that gfortran is being used to compile a C file. If you use the default cc compiler, it would compile just fine:

$ cc -c ./src/filesystem_utilities.c -o build/gfortran_2A42023B310FA28D/fpm/src_filesystem_utilities.c.o

Since I now can't compile fpm in the first place, it's not easy to fix for me.

This works in Windows: set FPM_C_COMPILER=gcc - an equivalent command in macOS may help.

[certik]

That works! I did:

FPM_C_COMPILER=clang fpm build

And this now builds fpm on my macOS. Thank you @brocolis.

[certik]

I am going to keep this issue open until either:

• This just works out of the box
• Or there is a clear error message with this hint to use FPM_C_COMPILER=clang.

I think fpm should now that gfortran can't compile C files on macOS (for whatever reason).

[awvwgk]

Can you provide the output of conda list? This is incredible helpful for troubleshooting conda related issues.

I think you might be hitting conda-forge/gfortran_osx-64-feedstock#11, which has been lingered in the GCC toolchain for OSX for quite a while now and has only been fixed recently.

[awvwgk]

This should be solved with #527 now.