pgfopts: arguments with spaces don't play well with babel - pdflatex

Question

If I define a new package like this
\NeedsTeXFormat{LaTeX2e}
\ProvidesClass{myPlanning}[2022/07/16 my Planning class]
\LoadClass[french]{article}
\RequirePackage{pgfopts}
\pgfkeys{
/myOrg/.cd,
lang/.initial = english , lang/.store in = \myOrg#lang,
title/.initial = title , title/.store in = \myOrg#title,
}
\ProcessPgfOptions{/myOrg}
\RequirePackage[\myOrg#lang]{babel}
and I try to compile this document
\documentclass[lang=french,title={truc bidul}]{myPlanning}
\begin{document}
some text here
\end{document}
I get the following error:
This is pdfTeX, Version 3.141592653-2.6-1.40.22 (TeX Live 2022/dev/Debian) (preloaded format=pdflatex)
restricted \write18 enabled.
entering extended mode
(./Test.tex
LaTeX2e <2021-11-15> patch level 1
L3 programming layer <2022-01-21>
(/home/hylkema/texmf/tex/latex/local/Org/myPlanning.cls
Document Class: myPlanning 2022/07/16 my Planning class
(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls
Document Class: article 2021/10/04 v1.4n Standard LaTeX document class
(/usr/share/texlive/texmf-dist/tex/latex/base/size10.clo))
(/usr/share/texlive/texmf-dist/tex/latex/pgfopts/pgfopts.sty
(/usr/share/texlive/texmf-dist/tex/latex/pgf/utilities/pgfkeys.sty
(/usr/share/texlive/texmf-dist/tex/generic/pgf/utilities/pgfkeys.code.tex
(/usr/share/texlive/texmf-dist/tex/generic/pgf/utilities/pgfkeysfiltered.code.t
ex))))) (/usr/share/texlive/texmf-dist/tex/generic/babel/babel.sty
(/usr/share/texlive/texmf-dist/tex/generic/babel/txtbabel.def)
(/usr/share/texlive/texmf-dist/tex/generic/babel-french/french.ldf)
! LaTeX Error: Missing \begin{document}.
See the LaTeX manual or LaTeX Companion for explanation.
Type H <return> for immediate help.
...
l.4261 \ifin#\edef\bbl#tempc{\bbl#tempb}\fi}
?
However, if I compile this (No spaces in the title argument):
\documentclass[lang=french,title=truc]{myPlanning}
\begin{document}
some text here
\end{document}
It compiles fine with no errors.
What's more, the first document with spaces in the title argument compiles fine if I remove the \RequirePackage[\myOrg#lang]{babel} line from the package definition.
Is this a known problem and is there a solution ?
Thanks for your help,
Jouke

Answer 1

Update: The underlying issue was fixed in upstream babel on 2022-11-24 and should be resolved in the next release.
The issue is not the key=value parser but a code block of babel that tries to detect whether the wrong language is loaded if it got both options from the \documentclass and options when the package was called. That being said, pgfopts isn't up-to-date with current LaTeX (there were substantial changes to the option-system about a year ago that pgfopts has not yet followed suit), the only solutions to key=value options that are compatible to my knowledge are the builtin mechanism and expkv-opt.
But as I said, neither will solve your issue. Using main=\myOrg#lang in the options of babel however will, as if you used the main-option the problematic code of babel will not be used. So if you change your class to the following the only (admittedly strange) warning regarding your options you'll get will be
LaTeX Warning: Unused global option(s):
[french].
(but that stems from your strange usage of \LoadClass, in which article will add french to the unused options list though it isn't in the global options list, hence babel will not pick it up and remove it from said list).
\NeedsTeXFormat{LaTeX2e}
\ProvidesClass{myPlanning}[2022/07/16 my Planning class]
\LoadClassWithOptions{article}
\RequirePackage{pgfopts}
\pgfkeys{
/myOrg/.cd
,lang/.initial = english
,lang/.store in = \myOrg#lang
,title/.initial = title
,title/.store in = \myOrg#title,
}
\ProcessPgfOptions{/myOrg}
\RequirePackage[main=\myOrg#lang]{babel}