$ git clone -n https://src.fedoraproject.org/rpms/python-stestr.git /var/lib/mock/f40-build-2155495-50918/root/chroot_tmpdir/scmroot/python-stestr
Cloning into '/var/lib/mock/f40-build-2155495-50918/root/chroot_tmpdir/scmroot/python-stestr'...
$ git fetch origin 6225719ea75855eed106ddfb3fe3e80550e39d8b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-stestr
 * [new ref]         6225719ea75855eed106ddfb3fe3e80550e39d8b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6225719 Update to 4.1.0 (rhbz#2239471)