$ git clone -n https://src.fedoraproject.org/rpms/rust-scx_rusty.git /var/lib/mock/f40-build-1967871-25215/root/chroot_tmpdir/scmroot/rust-scx_rusty
Cloning into '/var/lib/mock/f40-build-1967871-25215/root/chroot_tmpdir/scmroot/rust-scx_rusty'...
$ git fetch origin ca589e8c25924e7b40fa9b7b04c77a789cd627f8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-scx_rusty
 * [new ref]         ca589e8c25924e7b40fa9b7b04c77a789cd627f8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ca589e8 Rebuild with Rust 1.78 to fix incomplete debuginfo and backtraces