$ git clone -n https://src.fedoraproject.org/rpms/python-curtsies.git /var/lib/mock/f39-build-1454596-32909/root/chroot_tmpdir/scmroot/python-curtsies
Cloning into '/var/lib/mock/f39-build-1454596-32909/root/chroot_tmpdir/scmroot/python-curtsies'...
$ git fetch origin d1e636aed039710e3ef5c86adde7b15451aa7f5d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-curtsies
 * [new ref]         d1e636aed039710e3ef5c86adde7b15451aa7f5d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d1e636a Rebuild