$ git clone -n https://src.fedoraproject.org/rpms/python-rxjson.git /var/lib/mock/f45-build-32839-664/root/chroot_tmpdir/scmroot/python-rxjson
Cloning into '/var/lib/mock/f45-build-32839-664/root/chroot_tmpdir/scmroot/python-rxjson'...
$ git fetch origin 2e12d4a4324ce569a111b65f71a432325911e8fa:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/python-rxjson
 * [new ref]         2e12d4a4324ce569a111b65f71a432325911e8fa -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 2e12d4a Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild