Fwd: LilyPond | Configure --with-flexlexer-dir does not stick (#6138)

[Dan Eble]

https://gitlab.com/lilypond/lilypond/-/issues/6138#note_589638792

> Enrico Maria Crisostomo commented:
> 
> I actually complain about this! I came here to search for this issue before 
> sending a PR. We're hitting this in MacPorts and we're actually patching 
> configure.ac ourselves.
> 
> https://trac.macports.org/ticket/62801 
> https://github.com/macports/macports-ports/pull/11183

This could be interpreted as a request to release 2.23.3.
— 
Dan