$ git clone -n https://src.fedoraproject.org/rpms/gap-pkg-lins.git /var/lib/mock/f41-build-side-1-3108691-39383/root/chroot_tmpdir/scmroot/gap-pkg-lins
Cloning into '/var/lib/mock/f41-build-side-1-3108691-39383/root/chroot_tmpdir/scmroot/gap-pkg-lins'...
$ git fetch origin 3fbbcf51e6d5851d1b50b3a813e6defb74bf2983:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gap-pkg-lins
 * [new ref]         3fbbcf51e6d5851d1b50b3a813e6defb74bf2983 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3fbbcf5 Initial RPM