$ git clone -n https://src.fedoraproject.org/rpms/gap-pkg-corelg.git /var/lib/mock/f38-build-side-42-init-devel-1015881-29484/root/chroot_tmpdir/scmroot/gap-pkg-corelg
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1015881-29484/root/chroot_tmpdir/scmroot/gap-pkg-corelg'...
$ git fetch origin 378c85da70afffdaf139396092932ce481285932:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gap-pkg-corelg
 * [new ref]         378c85da70afffdaf139396092932ce481285932 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 378c85d Use the %gap_arches macro.