$ git clone -n https://src.fedoraproject.org/rpms/R-rex.git /var/lib/mock/f40-build-2053321-49093/root/chroot_tmpdir/scmroot/R-rex
Cloning into '/var/lib/mock/f40-build-2053321-49093/root/chroot_tmpdir/scmroot/R-rex'...
$ git fetch origin 378c8e6fc1a313176eda7d356e70af23c5beb402:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-rex
 * [new ref]         378c8e6fc1a313176eda7d356e70af23c5beb402 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 378c8e6 Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild