$ git clone -n https://src.fedoraproject.org/rpms/rust-gix-dir.git /var/lib/mock/f41-build-700573-12889/root/chroot_tmpdir/scmroot/rust-gix-dir
Cloning into '/var/lib/mock/f41-build-700573-12889/root/chroot_tmpdir/scmroot/rust-gix-dir'...
$ git fetch origin 964f79bfe226b59ee26aa9bd44a7d0b93e2e83df:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gix-dir
 * [new ref]         964f79bfe226b59ee26aa9bd44a7d0b93e2e83df -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 964f79b Initial package (rhbz#2273625)