$ git clone -n https://src.fedoraproject.org/rpms/gap-pkg-singular.git /var/lib/mock/f38-build-side-42-init-devel-925516-28744/root/chroot_tmpdir/scmroot/gap-pkg-singular
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-925516-28744/root/chroot_tmpdir/scmroot/gap-pkg-singular'...
$ git fetch origin d591eae6093179f50ec1cc3397a2ce683adfa933:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gap-pkg-singular
 * [new ref]         d591eae6093179f50ec1cc3397a2ce683adfa933 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d591eae Use the %gap_arches macro.