I was surprised to wake up this morning and find that my graalvm-oracle 25-EA PR was merged. (It looks like the graalvm-oracle 24 PR should also be merged soon.)

So, as of now the jdk-ea-25 branch of https://github.com/nixpkgs-jdk-ea/nixpkgs does not differ from upstream and is of no use. I will try to update the temurin-bin 25-EA PR next week.

Honestly, for me it has worked pretty reliably outside of NixOS. I think there's a lot of false information on the internet, where people got stuck with a problem, then tried a bunch of different things without a structured process and somewhere in the middle they ran gralde clean and deleted all cashes. Then when they get unstuck they claim "cleaning and deleting all cashes will fix your problems", which is not the case most of the time.

In this particular case, I suspect that one of the jars from Gradle's native platform does something that doesn't work correctly on NixOS. Maybe it expects something to be in an FHS location, or something like that.

Right now, I don't know how we would fix this, because we can't install a fixed version of that jar into the cache, because we don't know the cache location beforehands.

ollijh has requested that we bump the default Gradle version to 9 as part of this PR, but to me this seems premature. I would think that the individual package maintainers should update individually and perhaps follow what the upstream packages are doing. And projects that use non-built-in plugins often need to wait for plugins to be updated.

I tried bumping three packages selected arbitrarily and none of them worked. See https://github.com/NixOS/nixpkgs/pull/421047#issuecomment-3189716199