$ git clone -n https://src.fedoraproject.org/rpms/ghc-crypton.git /var/lib/mock/f41-build-839649-160289/root/chroot_tmpdir/scmroot/ghc-crypton
Cloning into '/var/lib/mock/f41-build-839649-160289/root/chroot_tmpdir/scmroot/ghc-crypton'...
$ git fetch origin c326f63bbbcf7cab4af0871277fdc3ae87782b27:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-crypton
 * [new ref]         c326f63bbbcf7cab4af0871277fdc3ae87782b27 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c326f63 bump release