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[4.2.0-489] SCSS for TreePanel complains of undefined variable $form-checkbox-size
When I create a new application, and include a TreePanel, the resulting application can not be built because the ext-theme-neutral/sass/src/tree/Panel.scss file refers to the SASS variable '$form-checkbox-size'.
This is defined in ext-theme-neutral/sass/var/form/field/Checkbox.scss - but this is not included in the generated <app>-all.scss file by default.
If you put an explicit requirement into your app for Ext.form.field.Checkbox, then the app builds.
Thanks for the report! I have opened a bug in our bug tracker.