I have an Extjs application that I have retrofitted into a Sencha Cmd generated app to be able to minify & concatenate js and css files. The build process runs fine but I see the following errors when I run the application.

The lines corresponding to the error are:
and

I guess my 2 questions are :
- Is Sencha Cmd the only reliable way to minify & concatenate all files of an extjs application? I have tried using Yuicompressor to minify individual files and concatenate manually , however I was not able to figure out how to easily manage dependencies of the extJS application.
- How can I get around the issue above with the build generated with Sencha cmd? Is there something that I am missing?
I am using ExtJS 4.2.1 and Sencha Cmd 4(have tried with 5 as well).