$ git clone -n https://src.fedoraproject.org/rpms/golang-github-bep-overlayfs.git /var/lib/mock/f40-build-1947035-25183/root/chroot_tmpdir/scmroot/golang-github-bep-overlayfs
Cloning into '/var/lib/mock/f40-build-1947035-25183/root/chroot_tmpdir/scmroot/golang-github-bep-overlayfs'...
$ git fetch origin bc598c995d67e3c0bdfedacb603bddc06efce585:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/golang-github-bep-overlayfs
 * [new ref]         bc598c995d67e3c0bdfedacb603bddc06efce585 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bc598c9 Update to 0.9.2