Re: Texinfo 7.1 released

[Gavin Smith]

On Sun, Oct 22, 2023 at 06:37:39PM +0300, Eli Zaretskii wrote:
> > Date: Sun, 22 Oct 2023 17:30:15 +0300
> > From: Eli Zaretskii <eliz@gnu.org>
> > Cc: bug-texinfo@gnu.org
> > 
> > > From: Gavin Smith <gavinsmith0123@gmail.com>
> > > Date: Sun, 22 Oct 2023 14:23:53 +0100
> > > Cc: bug-texinfo@gnu.org
> > > 
> > > > > First, check that the Perl extension modules are actually being used. 
> > > > >  Try
> > > > > setting the TEXINFO_XS environment variable to "require" or "debug".
> > > > 
> > > > I don't need to do that, I already verified that extensions are used
> > > > when I worked on the pretests (which, as you might remember, caused
> > > > Perl to crash at first).
> > > 
> > > I'd expected so, just wanted to make sure.
> > 
> > Surprise: running with TEXINFO_XS=omit _reduces_ the elapsed time of
> > producing the Emacs ELisp manual from 1:21.16 to 0:36.97.
> 
> Another data point: running with TEXINFO_XS_PARSER=0 takes 1:34.4 min,
> so it sounds like the slowdown is due to some XS module other than the
> parser module.  Is there a way to disable additional modules one by
> one?

This is most surprising, but promising that we're getting close to the
problem.

The simplest way to disable XS modules would be to delete or rename
the libtool files that are used for loading them.  If you run with
TEXINFO_XS=debug, you can see which modules are loaded.  With Texinfo 7.1,
lines like the following would be printed:

found ../tp/../tp/Texinfo/XS/Parsetexi.la
found ../tp/../tp/Texinfo/XS/MiscXS.la
found ../tp/../tp/Texinfo/XS/XSParagraph.la

You could then disable modules with e.g.

mv ../tp/../tp/Texinfo/XS/XSParagraph.la{,.disable}

or

mv ../tp/../tp/Texinfo/XS/MiscXS.la{,.disable}

As long as you don't run "make", texi2any will not then be able to find the
modules.  Hopefully this will reveal that one of these modules is responsible
for the slowdown.