texi2any C code still built even though XS modules were disabled

On Sat, Jan 17, 2026 at 11:56:20AM +0200, Eli Zaretskii wrote:
> > From: Gavin Smith <[email protected]>
> > Date: Thu, 15 Jan 2026 16:58:13 +0000
> > Cc: [email protected], [email protected]
> > 
> > > IOW, this warning was expected, but was missing.  I see that this
> > > warning comes from texi2any.c:merge_opened_files, but I don't know how
> > > to investigate the reason(s) -- any hints?
> > 
> > It should not come from texi2any.c because that is the alternative
> > ctexi2any implementation that is not used by default.
> 
> Oh, so the "--enable-c-texi2any" configure-time option defaults to
> "no", not to "detect"?  I thought it defaults to "detect", because
> "./configure --help" says "Use texi2any program implemented in C if
> possible", and I see ctexi2any.exe was built as part of the build, so
> evidently that _was_ possible.  Then why isn't it used by the test
> suite (and not installed, as I say in my previous message)?

I don't know why it's built when it's not used.

If I run "./configure PERL_EXT_CC=failcc", this completes successfully
and disables XS modules:

configure: error: in '/home/g/src/texinfo/GIT/tta/perl/CheckXS':
configure: error: C compiler cannot create executables
See 'config.log' for more details
configure: error: ./configure failed for perl/CheckXS
configure: building Perl extension (XS) modules will be disabled

"make" does appear to complete successully (which it didn't before),
but only after a lot of time building C texi2any code.

But then "make check" fails badly.

$ perl -w t/02coverage.t
ok 1
perl: symbol lookup error: t//../../C/.libs/libtexinfoxs.so.1: undefined symbol: newSVpv_utf8

According to the output of "TEXINFO_XS=debug perl -w t/02coverage.t", a large
amount of C libraries and XS overrides are loaded anyway.