$ git clone -n https://src.fedoraproject.org/rpms/rust-uu_cksum.git /var/lib/mock/f40-build-704023-12986/root/chroot_tmpdir/scmroot/rust-uu_cksum
Cloning into '/var/lib/mock/f40-build-704023-12986/root/chroot_tmpdir/scmroot/rust-uu_cksum'...
$ git fetch origin 09aae06045ba113dcae915f9a8b59fcfef40b42d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-uu_cksum
 * [new ref]         09aae06045ba113dcae915f9a8b59fcfef40b42d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 09aae06 Rebuild with Rust 1.78 to fix incomplete debuginfo and backtraces