$ git clone -n https://src.fedoraproject.org/rpms/darktable.git /var/lib/mock/f38-build-side-42-init-devel-613614-26297/root/chroot_tmpdir/scmroot/darktable
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-613614-26297/root/chroot_tmpdir/scmroot/darktable'...
$ git fetch origin b75da7bc162794560564faded5b642e0a3e350b0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/darktable
 * [new ref]         b75da7bc162794560564faded5b642e0a3e350b0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b75da7b Disable LTO on aarch64