$ git clone -n https://src.fedoraproject.org/rpms/rust-uu_join.git /var/lib/mock/f41-build-810828-146963/root/chroot_tmpdir/scmroot/rust-uu_join
Cloning into '/var/lib/mock/f41-build-810828-146963/root/chroot_tmpdir/scmroot/rust-uu_join'...
$ git fetch origin 75b5ac72c6f86d93aa7329ba4118d38a8dd31bc1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-uu_join
 * [new ref]         75b5ac72c6f86d93aa7329ba4118d38a8dd31bc1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 75b5ac7 Rebuild with Rust 1.78 to fix incomplete debuginfo and backtraces