$ git clone -n https://src.fedoraproject.org/rpms/ghc-iso8601-time.git /var/lib/mock/f41-build-839423-160145/root/chroot_tmpdir/scmroot/ghc-iso8601-time
Cloning into '/var/lib/mock/f41-build-839423-160145/root/chroot_tmpdir/scmroot/ghc-iso8601-time'...
$ git fetch origin cdbb81346da0bbbbccaf2659f2e05a62ccd38e18:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-iso8601-time
 * [new ref]         cdbb81346da0bbbbccaf2659f2e05a62ccd38e18 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cdbb813 bump release