bootstrap: couldn't find path: $path, true

[JanStevens]

rake torba:pack
/app/vendor/assets/torba/cache/bootstrap-sass-ac6b4156/assets/stylesheets/$path, true
Couldn't find an asset with path '/app/vendor/assets/torba/cache/bootstrap-sass-ac6b4156/assets/stylesheets/$path, true'.
Make sure that you've imported all image/font assets mentioned in a stylesheet(-s).

Using following Torbafile

npm package: 'bootstrap-sass', version: '3.3.6',
  import: %w(assets/fonts/bootstrap/ assets/javascripts/bootstrap.js assets/stylesheets/)

I guess this has to do with the $path references here (_bootstrap-compass):

@function twbs-font-path($path) {
  @return font-url($path, true);
}

@function twbs-image-path($path) {
  @return image-url($path, true);
}

$bootstrap-sass-asset-helper: true;

[JanStevens]

A possible solution is to extend the regex in css_url_to_erb_asset_path and look for something that has a sane filename with extension:

[\w,\s-]+\.[A-Za-z]{4}