Re: emacs26, ucs-normalize.el, Symbol’s function definition is void: regexp-opt-charset

[Stefan Monnier]

>> Most likely regexp-opt gets loaded during the first run of "loadup", so
>> the compilation of ucs-normalize by the initial bootstrap-emacs
>> succeeds, even tough the compilation of that same file by the
>> `emacs` fails.
> Why is the first run of loadup different from the rest?

Because the first run of loadup is done with not-yet-compiled Elisp
files, so it loads a crapload more packages (because of things like
(eval-when-compile (require <foo>)) and autoloaded macros) than the
second run (performed after the preloaded files have all been
byte-compiled).


        Stefan