Instead of doing it from the main script the copy logic could live in the buildinstall thread. Once the koji task finishes, the outputs can be copied into compose/ dir. This needs to handle both lorax (1 copy) and legacy buildinstall (one task copied to multiple variants).

The advantages should be:

• simpler main script
• very tiny performance gain as we would copy the in parallel, possibly even while gather or createrepo phase is running