Problem width loading expl3-code.tex

[charlyms]

Hello, does anyone have an idea why latexml sometimes stucks at the point: | Digesting > Processing > Loading > Loading > Loading > Processing > Processing definitions C:/Users/.../.../l |ernel.tds/tex/latex/l3kernel/expl3-code.tex

[dginev]

Hi @charlyms ,

Yes, we are certainly aware of expl3 being slow. It is currently borderline unusable on texlive 2022 and older (~10 minutes per run) and completely unusable on texlive 2023 (~20 minutes of load time).

And that is on linux installations. You pay an additional slowdown penalty on Windows, which has a slower Perl interpreter.

There are 2 plans to address this in future latexml milestones:

• one is precompiling a format file for expl3-capable LaTeX, similarly to pdflatex
• A larger ongoing effort is entirely rewriting latexml in the Rust programming language

For now my best advice is to 1) try to avoid expl3 when possible and 2) use texlive 2021 or 2022 for optimal results.

[nschloe]

A larger ongoing effort is entirely rewriting latexml in the Rust programming language

:partying_face:

[orbita2d]

Can you not just save built artifacts for each package to a local directory? Surely better than a 20 min build time?

[dginev]

Can you not just save built artifacts for each package to a local directory? Surely better than a 20 min build time?

Yes, but not without making the right amount of preparatory work (see #2358 for an example of just one preliminary piece). There is merit to having a \dump-like capability in LaTeXML and @brucemiller already has a working prototype that could amortize the 20 minutes.

The 20 min build time is also a sign that LaTeX 3 support in LaTeXML is not properly tested on newer texlive versions (2023, 2024). There may be other regressions lurking there.

So the most sensible short term strategy is to "just" avoid such loads entirely for now.