$ git clone -n https://src.fedoraproject.org/rpms/frozen-bubble.git /var/lib/mock/f45-build-9360-403/root/chroot_tmpdir/scmroot/frozen-bubble
Cloning into '/var/lib/mock/f45-build-9360-403/root/chroot_tmpdir/scmroot/frozen-bubble'...
$ git fetch origin 3c3bafed50a686d76669c9e761459480470711a6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/frozen-bubble
 * [new ref]         3c3bafed50a686d76669c9e761459480470711a6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3c3bafe Perl 5.44 rebuild