Error messages

[Pavel Sanda]

On Mon, Mar 06, 2023 at 11:38:22AM +0100, Pavel Sanda wrote:
> On Wed, Feb 22, 2023 at 10:52:14AM +0100, Jean-Pierre Chrétien wrote:
> > Dear developers
> > 
> > When I open the original UserGuide with 2.4.0dev, I see this in the calling
> > command window:
> > 
> > Warning: dvipng failed to generate images from lyxpreviewOuMJqr.dvi...
> > fallback to legacy method
> > Warning: epstopdf failed on page 1, file lyxpreviewOuMJqr.001
> > Warning: epstopdf failed on page 2, file lyxpreviewOuMJqr.002
> > [...] snip
> > Warning: epstopdf failed on page 109, file lyxpreviewOuMJqr.109
> > Warning: epstopdf failed on page 110, file lyxpreviewOuMJqr.110
> > Warning: Now trying to obtain failed previews through pdflatex
> > Warning: Failed to produce 1 preview snippet(s)
> > 
> > When I open the French version, I get only the last line.
> > 
> > Any clue ?
> 
> Ghostscript chokes on our dvi.
> If passed debug option to it via e.g. epstopdf --debug --gsopt=-dDEBUG lyxpreviewjGIxTU.ps
> one gets:
> Error: /typecheck in --div--
> 
> It seems related to hyperref, this page wrt preview+hyperref seems related
> https://github.com/latex3/hyperref/issues/213
> https://lists.gnu.org/archive/html/bug-auctex/2020-11/msg00000.html
> 
> I have no clue what 'latex shipout code' is and did not inspect further.

Apart from trying to figure out what's wrong with latex-preview I looked at
our sources and figured out that
1) although we see this error on console, the preview is still produced
   OK via backup pdf route
2) this issue is not new to 2.4. It is present in 2.3 as well - the only difference
   triggering this problem in UG is:

-\default_output_format pdf2
+\default_output_format default
   
   which was changed during 2.4 lifetime.

Given that the underlying problem is likely in latex-preview whose
maintainer is not interested in fixing (probably this) problem I would
leave the issue dormant.

Pavel