It happens quite often that questions are posted, which are on-topic on U&L but have good answers on another suitable Stackexchange Site (askubuntu, stackoverflow...).
What to do with questions like this?
- Duplicate (or let OP duplicate) the original working answer to improve U&L SE ?
- Migrate to the other SE site and mark as duplicate there ?
- Close the question as off-topic (as it suits other sites and has answers there ) ?