Description:

I don't use the AUR very often, but when I do, it's for some rather large packages like pycharm-professional with an installed size ~700MB. For packages like this, the `Compressing package...` step takes a surprisingly long time, so I dug around to see just what was going on:

1. It's building a tar.xz archive
2. It's not using `--threads=0` so that compression only using one of my 16 cores :-(

If the Bash code could be modified to do something like this, compression would go a lot faster and people with more than one core (most people these days) could make use of their machines better:

tar --use-compress-program='xz --threads=0' -cf projectname.tar.xz path/


Steps to reproduce:

1. makepkg -i
2. Wait :-)