If maven-compiler-plugin executes the validation tool, then you don't need to call it explicitly using the exec-maven-plugin. You'd have to configure Eclipse manually though. Or you could disable annotation processing in the maven-compiler-plugin and run the ValidationTool using the exec-maven-plugin (and m2e should execute it as soon as a file changes in your project).
Also, note that the "specific for Indigo" is actually "specific for m2e 1.0" (which, I believe, can be installed on Helios) -- You received this message because you are subscribed to the Google Groups "Google Web Toolkit" group. To view this discussion on the web visit https://groups.google.com/d/msg/google-web-toolkit/-/Hs_PGyhThhcJ. To post to this group, send email to google-web-toolkit@googlegroups.com. To unsubscribe from this group, send email to google-web-toolkit+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/google-web-toolkit?hl=en.