Currently, we have to refactor some parts of an ExtJS4 application for one of our clients. During the refactoring process we renamed some namespaces to fit the current naming schemes, which changed a little bit over the time.
We also run a PHP backend accepting REST calls from the ExtJS4 application, and we already refactored the backend application in the same way. Among other things we have a slice called "Import", and we renamed the related namespace in the frontend to contain the "Import" part, resulting in something like this: "App.foo.import.bar". That was not a good idea.
Starting the SenchaCmd building process, we issued a lot of "YUI C2009" errors in an unknown file. I know, very helpful...
We solved issue renaming the namespace to "importer", and the errors vanished.