Theme image not found, when button has no rounded-borders

[Just-Boris]

I want green not rounded button and create custom UI.

@include extjs-button-ui(
    /* UI + Scale */  'green-button-medium',
// ...
//colors, fonts, padding
// ...
  $border-radius: 0px
); 

Then I build theme using compass compile. But warnings like this appears in progress:

  WARNING: @theme-background-image: Theme image not found: ../images/btn/btn-green-button-medium-pressed-corners.gif
         on line 18 of ../../ext/resources/themes/stylesheets/ext4/default/mixins/_theme-background-image.scss 

This sprites doesn't need because this button hasn't rounded borders, but compass still write it. Built theme works correct but because of this warnings I may miss something really important.
I slice theme on sptites by sencha cmd, but these files still missing. How to hide or fix it?

[mitchellsimoens]

It will try to use the theme-background-image mixin only if $supports-border-radius and $compile-all variables are set to true, which they are by default. It does not go off the border radius you provide.

[Just-Boris]

It works good as temporary solution, but how do I be sure that $compile-all=false doesn't break something else?
Why not add to extjs-button-ui mixin config $frame, which will handle framing and rounded-borders?