$ git clone -n https://src.fedoraproject.org/rpms/R2spec.git /var/lib/mock/f42-build-3181743-40950/root/chroot_tmpdir/scmroot/R2spec
Cloning into '/var/lib/mock/f42-build-3181743-40950/root/chroot_tmpdir/scmroot/R2spec'...
$ git fetch origin b76c65c42f359cd12e33adcab4dfe5b5f50e18ee:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R2spec
 * [new ref]         b76c65c42f359cd12e33adcab4dfe5b5f50e18ee -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b76c65c Rebuilt for https://fedoraproject.org/wiki/Fedora_42_Mass_Rebuild