button-variant mixin not recognized under Atlas 3

My app has a custom button scss file that defines some custom button styling using the button-variant mixin defined in the _buttons.scss under Atals_Core. The custom styling worked fine in Studio Pro 8 using Atlas 2, but when migrating to Studio Pro 9.12.4 and Atlas 3, I get the error: Undefined mixin. I’ve navigated to the file in windows explorer and still see the mixin definition. What am I missing? Here is my definition in me custombuttons.scss .btn-primary-outline {     @include button-variant($btn-primary-bg, #fff, $btn-primary-bg, $btn-default-bg-hover);     border: 1px solid $btn-primary-bg; } If I comment the @include out it compiles fine so I know my main.scss is defined correctly.
1 answers

For anyone else experiencing this same or similar issue, Mendix support helped me out by telling me that in the main.scss file in my custom module I must explicitly import the mixin and exclusion variables. In my case it was:

@import "../../../theme/web/exclusion-variables";

@import "../../../themesource/atlas_core/web/core/base/mixins/buttons";

Hopefully this helps other along the way.