When I fork the Ant process everything is OK, SpringGuiRunner starts as i should.
(The reason I didn't fork was that I did want to get the error messages to find out which other dependencies I should have included - then forking is no good...)

The problem seems very similar to this over at Leiningen:
http://osdir.com/ml/clojure/2009-12/msg00874.html

I'm not sure what the issue is. It might be related to classloaders. This is something we will work on for 1.0. In general though I would recommend to use always a forked JVM for executing Java. 0.9-preview-3 has very good support for this, including automatically capturing the output from the forked process and printing it to the console:

task springGuiRunner2(type: JavaExec) {
   main = 'se.megalit.progress.SpringGuiRunner'
   classpath = sourceSets.main.runtimeClasspath 
}

alternatively

task springGuiRunner2 << {
   javaexec {
      main = 'se.megalit.progress.SpringGuiRunner'
      classpath = sourceSets.main.runtimeClasspath 
   }
}

By default the output is printed to the console to the standard log level. You can change this behavior and for example redirect the process output to debug.

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