ExtJS - sencha app build dependency error - build

Question

I'm trying to extend a third party class. The code is something like this. Note I'm specifying where to load openGL.view.
Ext.Loader.setPath({
'openGL.view': 'C:/Users/«username»/Documents/third-party/openGL/view/'
});
Ext.define('myOpenGL.view.Qxga',{
extend: 'openGL.view.Uxga',
alias: 'widget.qxga',
itemId: 'qxga',
requires: [
'openGL.view.Uxga',
'myOpenGL.view.QxgaController'
],
controller: 'QxgaController'
});
When I build it, I get errors like this:
[ERR] Failed to resolve dependency openGL.view.Uxga for file myOpenGL.view.Qxga
[ERR]
[ERR] BUILD FAILED
[ERR] com.sencha.exceptions.ExNotFound: Unknown definition for dependency : openGL.view.Uxga
[ERR]
[ERR] Total time: 6 seconds
[ERR] The following error occurred while executing this line:
C:\Users\«username»\Applications\Sencha\Cmd\5.1.0.26\plugins\ext\current\plugin.xml:403: The following error occurred while executing this line:
C:\Users\«username»\Documents\workspace\openGL\.sencha\app\build-impl.xml:378: The following error occurred while executing this line:
C:\Users\«username»\Documents\workspace\openGL\.sencha\app\init-impl.xml:303: com.sencha.exceptions.ExNotFound: Unknown definition for dependency : openGL.view.Uxga
Some questions:
Why isn't it finding openGL.view.Uxga?
I've read about modifying build-impl.xml, but with various degrees of success. What would I have to do, and is there a way to do the same without having to modify the file? Say some kind of override or command line parameter?
If there is a way to do this using setPath, the third-party directory may not be in the same place. Is there a way to include a Windows environment variable or something similar?

Answer 1

Sencha Cmd doesn't know about the Ext.Loader.setPath call, Cmd doesn't execute the JavaScript. Instead, in your app.json you can add C:/Users/«username»/Documents/third-party to the classpath config. classpath is a comma-delimited (I think it may even be able to be an array these days) list of paths Cmd will use to inspect the files within it to search for Ext JS classes (or via certain comment tags like #require and #class).
"classpath": "app,C:/Users/«username»/Documents/third-party"