$ git clone -n https://src.fedoraproject.org/rpms/python-migen.git /var/lib/mock/f40-build-1855106-24981/root/chroot_tmpdir/scmroot/python-migen
Cloning into '/var/lib/mock/f40-build-1855106-24981/root/chroot_tmpdir/scmroot/python-migen'...
$ git fetch origin adfab7926073045175b9452687c8f73d7931c8f5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-migen
 * [new ref]         adfab7926073045175b9452687c8f73d7931c8f5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at adfab79 update to newer snapshot