$ git clone -n https://src.fedoraproject.org/rpms/gulrak-filesystem.git /var/lib/mock/f45-build-13246-447/root/chroot_tmpdir/scmroot/gulrak-filesystem
Cloning into '/var/lib/mock/f45-build-13246-447/root/chroot_tmpdir/scmroot/gulrak-filesystem'...
$ git fetch origin 876fd9365c901f0582a814b51046e6ab126dde0e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gulrak-filesystem
 * [new ref]         876fd9365c901f0582a814b51046e6ab126dde0e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 876fd93 Update to 1.5.16 (close RHBZ#2502268)