the bug is exactly same described at:
if the proposed, but rejected, patch in the bug is applied, the "fp-lib-table files contain no library with nickname" warning disappears but the footprint preview does not work (shows nothing in the preview window).
what I have tried is reverting the patch in the bug (https://git.launchpad.net/kicad/patch/?id=9b1f2447b6368ff68ae22b0b3bcbd1a72c8f4a45 does not fix).
the build box is FreeBSD 13.0-CURRENT 1300121, amd64.
this bug still exists in kicad-6.0.5_1,2.