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Does that help?

I pushed those changes to TL for tonight.

Re spam, do (either of) you have a particular change in mind? Is there something specific in these warnings you are seeing? I cannot randomly guess what to do to pacify gmail, if it's possible at all.

Also this platform constantly shows me errors, that my messages to this bugtracker are spam.

Hi Henri,

I've just installed TL 2020 and your example compiles correctly for me. So maybe the regression had been fixed already? I guess TL version used in you CI uses slightly older version of LaTeX kernel and it will be fixed in the following updates.

I don't know whether this has been fixed but now with TeX Live 2020 an even simpler document immediately fails.
\documentclass{article} \def\pgfsysdriver{pgfsys-tex4ht.def} \usepackage{tikz} \begin{document} \end{document} This crashes with
Runaway argument? \fi ^^M%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%\ETC. ! TeX capacity exceeded, sorry [main memory size=500000]. l.644 \Configure{TIT LE+}{\HCode{\jobname.\:html}} I'm sorry, but tex4ht has become completely unusable with TikZ recently and I might have to drop support for it if it continues to fail my CI.

I was able to construct a minimal example. This typesets correctly with latex, but causes a stack overflow with make4ht.
documentclass{article} \ifdefined\HCode \def\pgfsysdriver{pgfsys-tex4ht.def} \fi \usepackage{tikz} \usepackage{todonotes} \begin{document} \end{document}

Generating the pgfmanual for tex4ht started failing recently with the error:

! TeX capacity exceeded, sorry [input stack size=5000].
\use:tikzlibrary #1->\use:tikzlibrary {#1
}\find:externalize #1external\@nil
l.32 \usetikzlibrary{positioning}

I traced this error back to r666 of tex4ht. Manually reverting the change, i.e. adding this code to the preamble removes the error.

\def\@onefilewithoptions#1[#2]{%
\let\:temp\@reset@ptions
\def\@reset@ptions{%
\let\@reset@ptions\:temp
\edef\TivhTcats{%
\catcode`:=\the\catcode`:%
\catcode`@=\the\catcode`@}%
\catcode`\:=11 \catcode`\@=11
\a:usepackage
\TivhTcats
}%
\def\:currentoptions{#2}
\:onefilewithoptions#1[#2]}