Might be a problem in some other package - I downgraded texlive-latex-extra to 2020.20200925-1, 2020.20200804-3 and finally to 2020.20200629-1 (that one along with old texlive-luatex) and nothing changed.
Output file timestamps show I have successfully used powersem package on 2020-09-08 21:39 2020-09-29 20:58 2020-10-28 09:05 2020-11-11 10:30 2020-11-17 18:16 2020-11-24 21:13 2020-12-02 08:54 maybe too but I remember some trouble so perhaps I took earlier output file Times of texlive-latex-extra updates from dpkg logs 2020-08-06 13:05:45 upgrade texlive-latex-extra:all 2020.20200629-1 2020.20200804-1 2020-08-10 14:11:07 upgrade texlive-latex-extra:all 2020.20200804-1 2020.20200804-2 2020-08-13 09:16:38 upgrade texlive-latex-extra:all 2020.20200804-2 2020.20200804-3 2020-10-01 13:15:11 upgrade texlive-latex-extra:all 2020.20200804-3 2020.20200925-1 2020-12-01 10:29:39 upgrade texlive-latex-extra:all 2020.20200925-1 2020.20201129-1 2020-12-09 09:23:18 upgrade texlive-latex-extra:all 2020.20201129-1 2020.20201129-1 2020-12-09 10:35:42 upgrade texlive-latex-extra:all 2020.20201129-1 2020.20200925-1 2020-12-09 10:37:52 upgrade texlive-latex-extra:all 2020.20200925-1 2020.20200804-3 2020-12-09 10:39:21 upgrade texlive-latex-extra:all 2020.20200804-3 2020.20200629-1 Therefore full texlive sets from 2020.20200804-3 and 2020.20200925-1 should have been good (always upgraded all possible packages) Downgraded/upgraded all of texlive-extra packages and texlive-luatex for deps to 2020.20200925-1, did not help. Downgraded all texlive packages except older texlive-binaries and texlive-lang* to 2020-09-25, it works! Upgraded texlive-base texlive-latex-extra texlive texlive-font-utils texlive-fonts-extra-links texlive-fonts-extra texlive-fonts-recommended to current 20201203 and tex-common 6.15 Still works. Upgraded texlive-latex-base texlive-latex-recommended as they came together and it breaks. So probably i's one of these two that can take over the bug report.
-- Meelis Roos