Failed to build custom mixin with Sencha Cmd "Failed to find mixin class"

Hello,

I created by own mixin class, placed it in my own library folder and added it as a mixin one of my application classes. Everything works fine in the development folder. However, when I try to create a production build, I get the following error.

[ERR] BUILD FAILED

[ERR] com.sencha.exceptions.ExNotFound: Failed to find mixin class: mymixin.language

[ERR]

[ERR] Total time: 6 seconds

[ERR] The following error occurred while executing this line:C:\Users\myaccount\bin\Sencha\Cmd\4.0.4.84\plugins\ext\4.2\plugin.xml:386: The following error occurred while executing this line:C:\falcon\dev\ui\trunk\apps\myapp_dev\.sencha\app\build-impl.xml:367: The following error occurred while executing this line:C:\falcon\dev\ui\trunk\apps\myapp_dev\.sencha\app\js-impl.xml:11: com.sencha.exceptions.ExNotFound: Failed to find mixin class: boseui.language9:35:39 PM"C:/Users/myaccount/bin/Sencha/Cmd/4.0.4.84/sencha" app refresh

I have been able to get it to work by doing one of the following:

- Placing my mixin class file in the app folder where SA puts the autogenerated JS files.

- Modifying .sencha/app/sencha.cfg to include the path to my library folder as follows:

app.classpath=${app.dir}/app,${app.dir}/app.js,../library

However, I'm concerned that the neither of the above methods are actually safe ways of doing this since both the app folder and sencha.cfg appear to be autogenerated by SA when the project is first created.

Is there a proper method for including custom mixin files in the application?

Thanks,

Ken.