I recently upgraded from 2.22 to 2.24 and have run into some problems with one of my tools. The tool is set up to define some some stuff (in the example attached below I’ve narrowed it down to be just a color), but only if that thing is not already defined. The reason for this is because the definitions are in included files. There’s a master style file which defines everything and then a variant style file where only some things are defined (the things that are different from the master style file). The master style file is included explicitly in the source files, while the variant style file is included automatically by lyluatex if certain conditions are met in the document, and that inclusion happens before the contents of the source file. This means I have to prevent a redefinition rather than exploit it. I was doing this just fine in 2.22, but 2.24 complains about definition being wrapped in a conditional. I believe this has to do with the switchover in Guile versions, but I don’t know enough about Guile to figure out how to fix it (and no, convert-ly does not help here).
Attached is my MWE.