$ git clone -n https://src.fedoraproject.org/rpms/rust-matches.git /var/lib/mock/f45-build-43135-800/root/chroot_tmpdir/scmroot/rust-matches
Cloning into '/var/lib/mock/f45-build-43135-800/root/chroot_tmpdir/scmroot/rust-matches'...
$ git fetch origin a38e31c3b4516b97b356c87d7dc7e1b0e7009c6b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-matches
 * [new ref]         a38e31c3b4516b97b356c87d7dc7e1b0e7009c6b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at a38e31c Regenerate with rust2rpm v28