$ git clone -n https://src.fedoraproject.org/rpms/gap.git /var/lib/mock/f40-build-800236-142898/root/chroot_tmpdir/scmroot/gap
Cloning into '/var/lib/mock/f40-build-800236-142898/root/chroot_tmpdir/scmroot/gap'...
$ git fetch origin 91c86d4c8457f09c997ebdc083514af11c41de37:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gap
 * [new ref]         91c86d4c8457f09c997ebdc083514af11c41de37 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 91c86d4 Version 4.13.0