had to comment out @extend %mui-font-style-headline; to get app to run

[jcollum]

in _LeftNav.scss, line 4:

@extend %mui-font-style-headline;

This failed, error:

ERROR in ./~/css-loader?sourceMap&modules&localIdentName=[name]__[local]___[hash:base64:5]!./~/postcss-loader!./~/sass-loader?outputStyle=expanded&includePaths[]=/Users/collumj/work/hackathon/api-web/app/scss&includePaths[]=/Users/collumj/work/hackathon/api-web/node_modules&sourceMap&sourceMapContents=true!./app/components/LeftNav/_LeftNav.scss
Module build failed: 
  @extend %mui-font-style-headline;
 ^
      ".logo" failed to @extend "%mui-font-style-headline".
The selector "%mui-font-style-headline" was not found.
Use "@extend %mui-font-style-headline !optional" if the extend should be able to fail.
      in /Users/collumj/work/hackathon/api-web/app/components/LeftNav/_LeftNav.scss (line 4, column 3)
 @ ./app/components/LeftNav/_LeftNav.scss 4:14-428 13:2-17:4 14:20-434

Commented the line out and the app loaded fine.

[ospfranco]

any permanent solution to this?