Crash when reloading on jbr_dcevm-17_0_1-osx-aarch64-b164.8

[mworzala]

When reloading using dcevm/hotswap agent on jbr_dcevm-17_0_1-osx-aarch64-b164.8, the reload happens and then the JVM crashes immediately. I have attached the crash report, let me know if any other information is helpful.

hs_err_pid17685.log

[mworzala]

Hmm some more context, on a simpler project it does not crash but also does not apply the reloaded changes and prints

HOTSWAP AGENT: 22:34:47.539 ERROR (org.hotswap.agent.plugin.jdk.JdkPlugin) - classReload() exception No such field java.beans.Introspector.declaredMethodCache on null.

in the terminal. This error popped up on the original project as well.

[skybber]

You can ignore the HA error message. HA is not fully ported to java17 now. The crash seems more serious, is it reproducible?

[mworzala]

It’s consistent in one project, doesn’t happen in another. Although in the latter case nothing is reloaded as far as I can tell.

[skybber]

Is it possible to describe steps how to reproduce it on your https://github.com/Minestom/Minestom project?

[mworzala]

1. git clone https://github.com/Minestom/Minestom
2. git checkout 529_extension_improvement
3. (the rest in IntelliJ for convenience)
4. Project/gradle jdk to JBR
5. Debug src/test/java/demo/Main with -XX:HotswapAgent=fatjar
6. Make an edit at src/main/java/net/minestom/server/instance/InstanceContainer#L465 (for example a system print)
7. Recompile/reload InstanceContainer.java
8. Crash

This is consistent on my machine. The crash does not seem consistent at other locations. That one always crashes though.

[skybber]

@mworzala thanks for great report. I've fix now for it, it should be included in next release.

[skybber]

@mworzala before patch will be available, you can use -XX:-UseEmptySlotsInSupers as a workaround for your issue.

[mworzala]

Looks like that's working, thanks for the quick responses and patch!

I will close the issue for now, but if you could make a comment when the next release happens that would be great.

[avu]

@skybber why did you reopened this issue? Is it not fixed yet?

[skybber]

already fixed in java17.