Re: [PATCH 6/6] Use Arch instead of Debian for sr.ht builds

On Tue, Feb 24, 2026 at 01:56:20PM +0100, Alejandro Colomar via Mutt-dev wrote:
> Hi Rene,
> 
> On 2026-02-24T13:41:26+0100, Rene Kita wrote:
> > This explains why it went so smooth with Arch. m-(
> > 
> > Running the build on Arch I get multiple errors of this kind:
> > browser.c:548:17: error: initialization discards 'const' qualifier from
> > pointer target type [-Werror=discarded-qualifiers]
> >   548 |       char *c = strrchr (d, '/');
> >       |                 ^~~~~~~
> > 
> > This is in function:
> > static int examine_directory (MUTTMENU *menu, struct browser_state *state,
> > 			      const char *d, const char *prefix).
> > 
> > AFAIU, strrchr is defined as: char * strrchr(const char *s, int c).
> 
> Being Arch, I suspect you're using the latest glibc.  C23 has changed
> the prototype of string search functions to use 'QChar', which is just
> a way of saying "the const qualifier, if present on the input, is
> preserved in the output".
> <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3220.pdf#subsubsection.7.26.5.6>
> 
> This makes it possible to write code that is more type-safe.
> 
> Since C23, the standard prototype for strrchr(3) is:
> 
> 	QChar *strrchr(QChar *s, int c);
> 
> which could be documented in a more C++-style way, with overloads:
> 
> 	char *strrchr(char *s, int c);
> 	const char *strrchr(const char *s, int c);
> 
> I now need to update the manual pages, and think I'm going to use the
> latter, although feel free to suggest some preference or some other way
> to document it.
> 
> The glibc commit that changed this was:
> 
> 	glibc.git cd748a63ab1a (2025-11-20; "Implement C23 const-preserving standard library macros")
> 
> which is contained in glibc-2.43.

Thanks, that explains it.

I let Kevin come up with a solution as he already said he wants to take
care of it somewhere downthread.