[FTBFS] package 'libproxool-java' (0.9.1-4ubuntu1) failed to build on natty

Build log of libproxool-java (0.9.1-4ubuntu1) on any architecture.

Error for build log:

test:
     [echo] Running tests, this can take a few minutes.
     [java] ......................Exception in thread "Prototyper" java.util.ConcurrentModificationException
     [java] at java.util.HashMap$HashIterator.nextEntry(HashMap.java:810)
     [java] at java.util.HashMap$KeyIterator.next(HashMap.java:845)
     [java] at java.util.AbstractCollection.toArray(AbstractCollection.java:188)
     [java] at org.logicalcobwebs.proxool.ConnectionPoolManager.getConnectionPools(ConnectionPoolManager.java:89)
     [java] at org.logicalcobwebs.proxool.PrototyperThread.run(PrototyperThread.java:38)
     [java] F........09 Dec 2010 10:33:28,014 [ERROR] {ConnectionPool.java:742} org.logicalcobwebs.proxool.addStateListener - Couldn't load class blah
     [java] java.lang.ClassNotFoundException: blah
     [java] at java.net.URLClassLoader$1.run(URLClassLoader.java:217)
     [java] at java.security.AccessController.doPrivileged(Native Method)
     [java] at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
     [java] at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
     [java] at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
     [java] at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
     [java] at java.lang.Class.forName0(Native Method)
     [java] at java.lang.Class.forName(Class.java:186)
     [java] at org.logicalcobwebs.proxool.ConnectionPool.setDefinition(ConnectionPool.java:740)
     [java] at org.logicalcobwebs.proxool.ProxoolFacade.updateConnectionPool(ProxoolFacade.java:594)
     [java] at org.logicalcobwebs.proxool.StateListenerTest.testAddStateListener(StateListenerTest.java:96)
     [java] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
     [java] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
     [java] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
     [java] at java.lang.reflect.Method.invoke(Method.java:616)
     [java] at junit.framework.TestCase.runTest(TestCase.java:164)
     [java] at junit.framework.TestCase.runBare(TestCase.java:130)
     [java] at junit.framework.TestResult$1.protect(TestResult.java:106)
     [java] at junit.framework.TestResult.runProtected(TestResult.java:124)
     [java] at junit.framework.TestResult.run(TestResult.java:109)
     [java] at junit.framework.TestCase.run(TestCase.java:120)
     [java] at junit.framework.TestSuite.runTest(TestSuite.java:230)
     [java] at junit.framework.TestSuite.run(TestSuite.java:225)
     [java] at junit.framework.TestSuite.runTest(TestSuite.java:230)
     [java] at junit.framework.TestSuite.run(TestSuite.java:225)
     [java] at junit.extensions.TestDecorator.basicRun(TestDecorator.java:24)
     [java] at junit.extensions.TestSetup$1.protect(TestSetup.java:21)
     [java] at junit.framework.TestResult.runProtected(TestResult.java:124)
     [java] at junit.extensions.TestSetup.run(TestSetup.java:25)
     [java] at junit.framework.TestSuite.runTest(TestSuite.java:230)
     [java] at junit.framework.TestSuite.run(TestSuite.java:225)
     [java] at junit.extensions.TestDecorator.basicRun(T...

So building on amd64 - I get the following junit output:

test:
     [echo] Running tests, this can take a few minutes.
     [java] ..............................28 Feb 2011 21:54:28,600 [ERROR] {ConnectionPool.java:742} org.logicalcobwebs.proxool.addStateListener - Couldn't load class blah
     [java] java.lang.ClassNotFoundException: blah
     [java] at java.net.URLClassLoader$1.run(URLClassLoader.java:217)
     [java] at java.security.AccessController.doPrivileged(Native Method)
     [java] at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
     [java] at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
     [java] at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:294)
     [java] at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
     [java] at java.lang.Class.forName0(Native Method)
     [java] at java.lang.Class.forName(Class.java:186)
     [java] at org.logicalcobwebs.proxool.ConnectionPool.setDefinition(ConnectionPool.java:740)
     [java] at org.logicalcobwebs.proxool.ProxoolFacade.updateConnectionPool(ProxoolFacade.java:594)
     [java] at org.logicalcobwebs.proxool.StateListenerTest.testAddStateListener(StateListenerTest.java:96)
     [java] at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
     [java] at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
     [java] at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
     [java] at java.lang.reflect.Method.invoke(Method.java:616)
     [java] at junit.framework.TestCase.runTest(TestCase.java:164)
     [java] at junit.framework.TestCase.runBare(TestCase.java:130)
     [java] at junit.framework.TestResult$1.protect(TestResult.java:106)
     [java] at junit.framework.TestResult.runProtected(TestResult.java:124)
     [java] at junit.framework.TestResult.run(TestResult.java:109)
     [java] at junit.framework.TestCase.run(TestCase.java:120)
     [java] at junit.framework.TestSuite.runTest(TestSuite.java:230)
     [java] at junit.framework.TestSuite.run(TestSuite.java:225)
     [java] at junit.framework.TestSuite.runTest(TestSuite.java:230)
     [java] at junit.framework.TestSuite.run(TestSuite.java:225)
     [java] at junit.extensions.TestDecorator.basicRun(TestDecorator.java:24)
     [java] at junit.extensions.TestSetup$1.protect(TestSetup.java:21)
     [java] at junit.framework.TestResult.runProtected(TestResult.java:124)
     [java] at junit.extensions.TestSetup.run(TestSetup.java:25)
     [java] at junit.framework.TestSuite.runTest(TestSuite.java:230)
     [java] at junit.framework.TestSuite.run(TestSuite.java:225)
     [java] at junit.extensions.TestDecorator.basicRun(TestDecorator.java:24)
     [java] at junit.extensions.TestSetup$1.protect(TestSetup.java:21)
     [java] at junit.framework.TestResult.runProtected(TestResult.java:124)
     [java] at junit.extensions.TestSetup.run(TestSetup.java:25)
     [java] at junit.textui.TestRunner.doRun(TestRunner.java:121)
     [java] at junit.textui.TestRunner.start(TestRunner.java:185)
     [java] at junit.textui.TestRunner.main(TestRunner.java:143)
     [java] ...........
     [java] .........
...

@Daviey - I can't seem to reproduce this build failure either locally or in a PPA - any ideas?

Build log from PPA - https://launchpad.net/~james-page/+archive/groovy-testing/+buildjob/2292359

This no longer seems to be an issue, perhaps fixed by accident with toolchain changes? Oh well.. :)