I expect it's the kind of thing that might be suitable for passthru.tests, to be manually run on an update, rather than blocking the build on Hydra

Yeah. And I also have the impression getting AQAVit running under Nix would be non-trivial. I don't think it is something the Nix Java team should prioritize in the short-run and it's not something I see myself having the time or inclination to tackle. But it might be nice to have eventually.

either the Temurin build scripts are a good fit for us and we can use them in our OpenJDK source builds, or they would make the derivation less maintainable or less flexible and so we should keep driving the OpenJDK build on our own

The individual working on it seems committed to doing it, so maybe we find out.

It seems like the core Nix Java team (however that is defined) should focus an a few JDKs as "first-tier" and a few more as "second-tier" and declare the rest as community supported. And this should be documented somewhere. Something like:

First-tier:

• OpenJDK
• GraalVM Community Edition

Second-tier:

• Temurin (because it's used for bootstrap)
• Zulu (because it's used on Darwin)

Community-supported:
Everything else (and if something isn't maintained it can be dropped)

It seems like the core Nix Java team (however that is defined) should focus an a few JDKs as "first-tier" and a few more as "second-tier" and declare the rest as community supported. And this should be documented somewhere. Something like:

First-tier:

• OpenJDK
• GraalVM Community Edition

Second-tier:

• Temurin (because it's used for bootstrap)
• Zulu (because it's used on Darwin)

Community-supported:

• Everything else (and if something isn't maintained it can be dropped)