Idea Project Runner building GWT app different than Idea GUI

Good morning,

I'm having trouble diagnosing Teamcity build failures on a GWT application that builds fine with the Idea GUI.  The errors occur with the GWT compiler which is apparently being called differently by the Teamcity agent than by the Idea GUI.  How can I test and replicate what the Teamcity agent is doing (using the Idea Project Runner)?  Thanks for any help you can provide.