LaTeX: package extract abuses internal LaTeX interfaces and seems to be highly incompatible with modern versions of LaTeX

[nsajko]

Heads up:

The LaTeX package extract, used in the draft document, seems to intrude into private parts of the implementation of LaTeX, with high potential of breaking stuff. Compiling std.pdf emits nasty warnings at the end of the process:

(\end occurred inside a group at level 1)

### semi simple group (level 1) entered at line 86 (\begingroup)
### bottom level 

Latexmk marks these warnings as "very important" (it might have been some different but equivalent wording, not sure).

See https://tex.stackexchange.com/questions/605890/extract-package-causes-unfinished-group

the package redefines \begin and \end and completly breaks the new hook system of LaTeX, I wouldn't use it.

Write the author. He probably can use the new hooks instead of destroying them, or he could ask for real interfaces instead of redefining internal commands.

extract was created in 2005, long before any hook system was even discussed. So the new LaTeX destroyed the extract package.

[jwakely]

The person who asked that question on stackexchange is the editor of the standard draft, so no heads up is needed :-)

The question was asked because it causes problems here, so it's already known.

[axelsommerfeldt]

Personally I find the term "abuses internal LaTeX interfaces" offensive; at the time when the extract package was written, "abusing" internal LaTeX interfaces was the only way to write such package in the first place. And blaming the author of the package for this does not really help either.

[tkoeppe]

Perhaps we can replace the use of extract with some other package? How about https://ctan.org/pkg/scontents?