amsthm, cleveref, \newtheorem, shared counter, \label

[alexanderperlis]

Thankfully firstaid seems to make amsthm and cleveref usable in many circumstances, allowing tagging experiments on existing documents.

Here's a particular combination that currently won't compile (on MacTeX, TeX Live 2024, both pdfTeX and LuaTeX, LaTeX2e 2024-11-01, L3 layer 2024-11-02, nor under pdflatex-dev or lualatex-dev, LaTeX2e 2025-06-01 pre-release-1 2024-12-18 branch, L3 layer 2024-12-09):

\DocumentMetadata{testphase={phase-III,firstaid}}
\documentclass{article}
\usepackage{amsthm}
\usepackage{cleveref}

\newtheorem{theorem}{Theorem}[section]
\newtheorem{proposition}[theorem]{Proposition}

\begin{document}

\begin{proposition}
\label{mylabel}   % <--- error ("Something's wrong--perhaps a missing \item")
\end{proposition}

\end{document}

Key ingredients:

• Loading amsthm before loading cleveref (as instructed in cleverref documentation)
• Loading cleveref before calling \newtheorem (as instructed in cleverref documentation)
• Defining a theorem type that uses someone else's counter
• Using \label with that theorem type

Error goes away with any one of the following (undesirable) changes:

• Comment-out \DocumentMetadata line
• Comment-out \usepackage{amsthm} line
• Comment-out \usepackage{cleveref} line
• Swap order of \usepackage{amsthm} and \usepackage{cleveref}
• Give proposition its own counter: \newtheorem{proposition}{Proposition}[section]
• Move \usepackage{cleveref} below the various \newtheorem

[krypt-n]

Quick notes (since I'm also interested in this combination of packages):

• the same compilation error happens for me without the \label

• using lualatex-dev (develop 2024-12-19 branch), I get a different error:

! LaTeX template Error: The instance '\l__block_block_instance_tl -\int_use:N
(template)              \g_block_nesting_depth_int ' of type 'block' is
(template)              unknown.

[u-fischer]

when cleveref is loaded after amsthm it overwrites the new tagging code for the theorems and so breaks tagging. Try what happens if you load it before amsthm, it is probably easier to solve whatever problem arisethere.

Or consider to use e.g. zref-clever instead of cleveref. cleveref contains so many patches that is is quite hard to make it fully tagging compatible.