$ git clone -n https://src.fedoraproject.org/rpms/rust-uu_dir.git /var/lib/mock/f41-build-810902-146981/root/chroot_tmpdir/scmroot/rust-uu_dir
Cloning into '/var/lib/mock/f41-build-810902-146981/root/chroot_tmpdir/scmroot/rust-uu_dir'...
$ git fetch origin c177a270bcb0285fde70de30f23ea9cd717321e8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-uu_dir
 * [new ref]         c177a270bcb0285fde70de30f23ea9cd717321e8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c177a27 Rebuild with Rust 1.78 to fix incomplete debuginfo and backtraces