Updating basictex did not trigger format rebuild

[Karl Berry]

P.S. Or, actually, ignore that. I think I'm totally wrong. The option is
about format creation at install time, not updates.

Also, another TL user reported the same problem of latex formats not
being rebuilt. I guess we are somehow missing a dependency for
rebuilding latex, despite all my efforts in that regard.

I don't think it is OS related, at least.