Lack of useful error messages when LaTeXImage fails

[dlglin]

When latex fails to compile a TikZ image for inclusion in hardcopy the user gets two warnings:

• Image file production failed. at [PG]/lib/LaTeXImage.pm line 265.
• Error generating graph for [WW]/htdocs/tmp/...

There doesn't appear to be a way to access the actual error messages produced by latex when trying to generate the image. In LaTeXImage.pm the temp files are all deleted regardless of whether the compilation was successful.

Two thoughts:

1. Add a conditional to LaTeXImage.pm that preserves the temp files if compilation failed or if preserve_temp_files is set.
2. If compilation fails for an image, then return the contents of the latex.err file in addition to the "Image file production failed" warning.

[drgrice1]

I realized that this is actually an invalid issue as stated. The LaTeXImage.pm module does provide useful error message when a pdf file fails to generate. For example, try the following not so minimal example:

DOCUMENT();

loadMacros('PGstandard.pl', 'PGML.pl', 'plots.pl', 'PGcourse.pl');

$plot = Plot();
$plot->image_type('TikZ');

$plot->add_function('x', 'x', 2, 2);

BEGIN_PGML
>>[!alt text!]{$plot}{400}<<
END_PGML

ENDDOCUMENT();

That is basically your degenerate domain problem with the image type switch to TikZ. Add that problem to a set, and open the problem in the set. You will see that in fact the LaTeXImage.pm already does what you suggest with your second idea. It in fact warns the entire contents of stdout from running latex.

The issue is not the LaTeXImage.pm module when used directly to generate an image. It is what happens when a hardcopy is generated that causes these warnings to be lost.

[drgrice1]

So this is still an issue with the LaTeXImage.pm module. I see that in the case that only the pdf file is generated for hardcopy, the stdout warnings are skipped. This happened when the TikZ.pm module was converted into the LaTeXImage.pm module and restructured for the PTX output.

[somiaj]

Fixed in #1329.