Duplicate Class Definition

[Dustin Barnes]

Every so often, I run into a compile error: 

[INFO] Collecting simulations...

[INFO] Exception in thread "main" java.lang.LinkageError: loader (instance of  scala/tools/nsc/interpreter/AbstractFileClassLoader): attempted  duplicate class definition for name: "com/mypackage/AbstractParentSimulation"

[INFO] at java.lang.ClassLoader.defineClass1(Native Method)

[INFO] at java.lang.ClassLoader.defineClass(ClassLoader.java:791)

[INFO] at java.lang.ClassLoader.defineClass(ClassLoader.java:634)

[INFO] at scala.tools.nsc.interpreter.AbstractFileClassLoader.findClass(AbstractFileClassLoader.scala:52)

[INFO] at com.excilys.ebi.gatling.app.Gatling$$anonfun$loadSimulationClasses$4.apply(Gatling.scala:205)

[INFO] at com.excilys.ebi.gatling.app.Gatling$$anonfun$loadSimulationClasses$4.apply(Gatling.scala:205)

[INFO] at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:233)

[INFO] at scala.collection.TraversableLike$$anonfun$map$1.apply(TraversableLike.scala:233)

[INFO] at scala.collection.LinearSeqOptimized$class.foreach(LinearSeqOptimized.scala:59)

[INFO] at scala.collection.immutable.List.foreach(List.scala:76)

[INFO] at scala.collection.TraversableLike$class.map(TraversableLike.scala:233)

[INFO] at scala.collection.immutable.List.map(List.scala:76)

[INFO] at com.excilys.ebi.gatling.app.Gatling.loadSimulationClasses(Gatling.scala:205)

[INFO] at com.excilys.ebi.gatling.app.Gatling.start(Gatling.scala:105)

[INFO] at com.excilys.ebi.gatling.app.Gatling$.main(Gatling.scala:69)

[INFO] at com.excilys.ebi.gatling.app.Gatling.main(Gatling.scala)

This is while running through the maven plugin. Basically, there are a bunch of simulation classes that extend a base simulation. 

This setup works on my windows machine and my ubuntu machine, but on the centos machine(s), it fails. Any tips on getting around this? 

[Stéphane Landelle]

Hello Dustin,

First time I see this one.

You say it happens randomly on your centos machine?

Stéphane

2012/8/24 Dustin Barnes <dustin...@gmail.com>

[Dustin Barnes]

Yeah. I ended up getting around it by removing the inheritance and using some includes. But I had identical versions of maven, and the java difference was 1.7.0_3 vs 1.7.0_6, all the rest of the dependencies the same. 

[Stéphane Landelle]

I think I pinned it: I was using ClassLoader.findClass instead of ClassLoader.loadClass. Once again, an example of poorly named java API, and my fault not reading the javadoc...

https://github.com/excilys/gatling/issues/665

Do you think you could build from sources and give it a try?

2012/8/25 Dustin Barnes <dustin...@gmail.com>

[Dustin Barnes]

I'll try to get to it on Monday. Thanks!

[Stéphane Landelle]

Thanks for reporting and have a nice week-end!

2012/8/25 Dustin Barnes <dustin...@gmail.com>

[Stéphane Landelle]

Hi Dustin,

Did you get the chance to test the fix?

Cheers,

Steph

[Dustin Barnes]

Sorry for the delay. Yes, this seems to have fixed this issue. Thanks!