I'm blocked by this bug (in fact, I filed #853937, which was merged with #853970, which points to #852611...).
- Re-running the command doesn't work (contrary to what suggested the first post in #852611). - Re-installing tex-common (ot texlive) doesn't work either. - The problem is bound to the system-installed /usr/share/texlive/texmf-dist/web2c/updmap.cfg, which I didn't ever touch (of course...). - It seems that I still can dis-upgrade my system, but the same error(s) happen on tex-common and texlive-lang-* packages. Any workaround would be welcome... -- Emmanuel Charpentier