Debug Grails application in GGTS 3.6.4, nothing happens, no error message

I am trying to debug a grails application (grails 2.5.0) with ggts 3.6.4. It worked several times without any problem, but now nothing happens. I click on the project thenDebug As Grails command Run App

The console just shows some pretty standard stuff that comes up every time I launch the application:

Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize=256m; support was removed in 8.0
objc[7403]: Class JavaLaunchHelper is implemented in both /Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/bin/java and /Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/libinstrument.dylib. One of the two will be used. Which one is undefined.
|Loading Grails 2.5.0
|Configuring classpath
.
|Environment set to development
.................................
|Packaging Grails application
...............................................
|Running Grails application
objc[7415]: Class JavaLaunchHelper is implemented in both /Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/bin/java and /Library/Java/JavaVirtualMachines/jdk1.8.0_45.jdk/Contents/Home/jre/lib/libinstrument.dylib. One of the two will be used. Which one is undefined.

      

        
        
        
      

    

Oddly enough, it worked several times before and I don't know what could have changed since I have the same project as my friends from git.