$ git clone -n https://src.fedoraproject.org/rpms/clang13.git /var/lib/mock/f39-build-1540455-36473/root/chroot_tmpdir/scmroot/clang13
Cloning into '/var/lib/mock/f39-build-1540455-36473/root/chroot_tmpdir/scmroot/clang13'...
$ git fetch origin 686e6dfe2d7a276d60bf8472e55341dd6c19102d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/clang13
 * [new ref]         686e6dfe2d7a276d60bf8472e55341dd6c19102d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 686e6df Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild