Today I've been iterating on changes in a shared library, and I find it very frustrating that trivial compile errors in the library source just result in "ErrorCollector" stacktraces, with no useful information. For instance, I had some iterations that failed because I was missing an import statement for a class I was referencing. I simply added the import for the missing class, and the error went away. However, I had to realize what class I was missing the import for. I've managed to get Eclipse to tell me when I have basic Groovy syntax errors, but it doesn't tell me if I'm missing an import for a referenced class.