Since the inception of Builder, it has used $XDG_CACHE_DIR for many things like custom installation paths, flatpak-builder state directories, out-of-tree build directories, code indexes, and more.

I finally got around to allowing for custom cache roots and now Builder will default to ~/Projects/.gnome-builder/ . If you’ve set a custom projects directory then .gnome-builder within that will be used.

You may also change this value globally or per-project in Preferences and/or Project Settings.