$ git clone -n https://src.fedoraproject.org/rpms/rust-uu_comm.git /var/lib/mock/f40-build-704030-12986/root/chroot_tmpdir/scmroot/rust-uu_comm
Cloning into '/var/lib/mock/f40-build-704030-12986/root/chroot_tmpdir/scmroot/rust-uu_comm'...
$ git fetch origin aff9d4f794f05da7866978d40f7cf04afbdcf304:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-uu_comm
 * [new ref]         aff9d4f794f05da7866978d40f7cf04afbdcf304 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at aff9d4f Rebuild with Rust 1.78 to fix incomplete debuginfo and backtraces