$ git clone -n https://src.fedoraproject.org/rpms/python-mitogen.git /var/lib/mock/f45-build-31582-654/root/chroot_tmpdir/scmroot/python-mitogen
Cloning into '/var/lib/mock/f45-build-31582-654/root/chroot_tmpdir/scmroot/python-mitogen'...
$ git fetch origin 9cc9edf5bfad7fd21c529aec504a942d5e627489:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-mitogen
 * [new ref]         9cc9edf5bfad7fd21c529aec504a942d5e627489 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9cc9edf Update to latest upstream release