bug#28242: Batch mode compiling: Error messages are displayed with "invalid character" glyph bounding symbols.

[Eli Zaretskii]

> Date: Sat, 26 Aug 2017 13:06:08 +0000
> From: Alan Mackenzie <acm@muc.de>
> 
> On my new PC (Gentoo GNU/Linux), byte compiling in batch mode (e.g. with
> make bootstrap in the master branch) is displaying warning messages with
> symbols "quoted" by the invalid character glyph (a solid square) rather
> than ` and '.  Presumably Emacs is attempting to use single curly
> quotes.
> 
> This is ugly and not helpful.  A fix would be appreciated.

You need to figure out why the logic in startup--setup-quote-display
isn't working in your case.