LinkageError when running Bundler in 9k

[iconara]

This has happened to me a few times when running bundle in 9k:

Java::JavaLang::LinkageError: loader (instance of  org/jruby/util/JRubyClassLoader): attempted  duplicate class definition for name: "org/bouncycastle/jcajce/provider/digest/SHA512$Digest"

Sometimes it happens, sometimes it don't. I haven't seen a pattern.

$ ruby -v
jruby 9000.dev-SNAPSHOT (2.1.2p142) 2014-11-05 624823a Java HotSpot(TM) 64-Bit Server VM 25.0-b70 on 1.8.0-b132 +jit [darwin-x86_64]
$ java -version
java version "1.8.0"
Java(TM) SE Runtime Environment (build 1.8.0-b132)
Java HotSpot(TM) 64-Bit Server VM (build 25.0-b70, mixed mode)

[iconara]

It happens almost every time I bundle for the first time in a new gemset. Sometimes I see the message more than once. I have BUNDLE_JOBS set to 8 so it wouldn't surprise me if this was a multi-threading issue.

[headius]

@iconara oh yeah, I bet it is a threading problem then. The error is caused by trying to load openssl in multiple threads at the same time; they both end up trying to define the same class at the same time.

A little synchronization on the classloader should do it, but I'll try to sort out something a little less brutal.

[headius]

Could you get a more complete stack trace? Try combinations of -d (debug mode causes load errors to show their exceptions) and -Xbacktrace.style=raw (shows raw JVM trace).

[iconara]

It took a few runs but finally I caught one. Feels like I got it all the time yesterday, but today it was really hard to make it happen:

https://gist.github.com/iconara/bb77e5b843de4d7a9683

Unfortunately there's no stack trace to the LinkageError. I think it's because Bundler recklessly rescues Exception during installation.

Hopefully there's something else in the output that can help you.

[iconara]

I patched my local Bundler to not swallow the exception and managed to get a stack trace: https://gist.github.com/iconara/bb77e5b843de4d7a9683#file-error

I also updated the gist with the full output (the LinkageError in the separate file stack trace is at the very bottom): https://gist.github.com/iconara/bb77e5b843de4d7a9683#file-full-output

[headius]

Ok thanks...tricky one to investigate but we'll figure it out.

[mkristian]

I can reproduce the error with oracle jdk7 and jdk8. open-jdk does not show errors (as often I tested it but oracle jdk immediately showed the error)