$ git clone -n https://src.fedoraproject.org/rpms/libguestfs.git /var/lib/mock/f39-build-1630077-39599/root/chroot_tmpdir/scmroot/libguestfs
Cloning into '/var/lib/mock/f39-build-1630077-39599/root/chroot_tmpdir/scmroot/libguestfs'...
$ git fetch origin 7f1b9ab59922175926d102ecb5d38a01ddc9b1e4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/libguestfs
 * [new ref]         7f1b9ab59922175926d102ecb5d38a01ddc9b1e4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7f1b9ab New upstream development branch 1.51.7