Which package provides libgomp1?

I try to run a python application which uses lightgbm on nixos and get the following error:

libgomp.so.1: cannot open shared object file: No such file or directory

I know there are separate packages in other distros to install libgomp, e.g. Debian’s libgomp1.

I did not manage to find out how libgomp is packaged in nixos. I looked into the gcc package and found the file libgomp.a in the lib directory. However, there is no dynamic library for libgomp. Why is that?

Using nix-index I found a reasonable candidate in libgcc.lib.

/nix/store/9fy9zzhf613xp0c3jsjxbjq6yp8afrsv-gcc-12.3.0-lib/lib/libgomp.la
/nix/store/9fy9zzhf613xp0c3jsjxbjq6yp8afrsv-gcc-12.3.0-lib/lib/libgomp.so
/nix/store/9fy9zzhf613xp0c3jsjxbjq6yp8afrsv-gcc-12.3.0-lib/lib/libgomp.so.1
/nix/store/9fy9zzhf613xp0c3jsjxbjq6yp8afrsv-gcc-12.3.0-lib/lib/libgomp.so.1.0.0

Thanks so much! This is what I looked for!

Do you know if it is discoverable using pkg-config? I’ve tried pkg-config --libs libgomp but it is not found.

Then, I added libgcc.lib to my dev shell’s buildInputs and I my python scripts run with the following hack:

export LD_LIBRARY_PATH=${pkgs.lib.makeLibraryPath [
    pkgs.libgcc.lib
]}

I don’t know if this is the way it’s supposed to work, though.

I think the output would need to have a .pc config file for that to work.