Well, the error message is easy to get rid of. The real question is whether the plugin would really work with that fix.

I was under the impression that NPAPI plugins didn't work at all with such recent versions of Firefox? If that's wrong, then this PR is also wrong. :-P

Correct (Flash has an exception). It stopped in 52, and that's the oldest ESR we have. There might be more such cases in the wrapper, even on master.

OK, since our ESR version reaches that far back, I'll close this. Thanks for noticing. :)

To be clear, the oldest one we have (52) should be without NPAPI support already (except Flash).

Oh, off-by-1 misunderstanding. 😆

I suspect Mozilla specifically wanted to get rid of it in the ESR version, due to NPAPI being a security nightmare.

I just wonder if these obsoleted nixpkgs config options should be just silently ignored (the current code does that) or if there should be at least a warning printed.

Do we have any infrastructure to support that at all? We'd need some way to actually evaluate possibly-existing-but-no-longer-active configuration and throw an error on that.

I meant simply having the wrapper check non-existence of those options instead of using them.