I have been playing with Upp for a few weeks now and have formed some opinions which I would like to share.
theIDE does not compile the file in the editor. It just says it does. It should compile the file in the editor whether it is in a nest or not. Note that this does not require tracking whether the file is "Dirty" or not. Pressing a compile button should "force" a compile of that file reguardless of its state.
Just to make it sure, is the problem that the file is not in the "project"?