We have one project that has a fairly complex NAnt build process, and we're trying to get it to work under QuickBuild. We noticed that the step was getting flagged as a success even when the build itself failed. Since we're paying customers, we looked at the source for this plugin.

It looks like the step's run method scans stdout and stderr for the string "BUILD SUCCEEDED". If that string appears ANYWHERE in the build output, the step is marked as a success. In our case, the problem is that one of our NAnt scripts calls another. So out build output can contain the string "BUILD SUCCEEDED" even in the case of a failure.

Comparing it to the MSBuild plugin, I think I see the problem. The NAnt plugin calls "getReturnCode", whereas the MSBuild plugin calls "checkReturnCode". I suspect that's the intended behavior - NAnt must exit with code 0 AND ALSO have produced the output string "BUILD SUCCEEDED".