$ git clone -n https://src.fedoraproject.org/rpms/gap-pkg-xmod.git /var/lib/mock/f42-build-59195561-6571706/root/chroot_tmpdir/scmroot/gap-pkg-xmod
Cloning into '/var/lib/mock/f42-build-59195561-6571706/root/chroot_tmpdir/scmroot/gap-pkg-xmod'...
$ git fetch origin 2faef40502c94ddbac87bd6b5c0b547e7cdc9da2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gap-pkg-xmod
 * [new ref]         2faef40502c94ddbac87bd6b5c0b547e7cdc9da2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2faef40 Version 2.93