Warning scss

Created by: MrKeiKun

Summary: I was browsing my production.logs over Gitlab Admin Logs then i found WARNING on line 54 of /home/git/gitlab/app/assets/stylesheets/sections/notes.scss: "ul.notes .discussion .discussion-body .file" failed to @extend ".borders".

Logs:

Started GET "/MrKeiKun/neko/commits/31a6b90e9d1837bfb72a03d4a3dd33bb29d34ecf/src/config" for 66.249.73.56 at 2014-02-12 23:20:59 +0800
Processing by Projects::CommitsController#show as */*
Parameters: {"project_id"=>"MrKeiKun/neko", "id"=>"31a6b90e9d1837bfb72a03d4a3dd33bb29d34ecf/src/config"}
Completed 401 Unauthorized in 6ms
Started GET "/MrKeiKun/neko/blob/637c78d55ec7d635c7150c308ac823290984cc15/doc/permissions.txt" for 66.249.73.56 at 2014-02-12 23:29:19 +0800
Processing by Projects::BlobController#show as */*
Parameters: {"project_id"=>"MrKeiKun/neko", "id"=>"637c78d55ec7d635c7150c308ac823290984cc15/doc/permissions.txt"}
Completed 401 Unauthorized in 5ms
WARNING on line 54 of /home/git/gitlab/app/assets/stylesheets/sections/notes.scss: "ul.notes .discussion .discussion-body .file" failed to @extend ".borders".
The selector ".borders" was not found.
This will be an error in future releases of Sass.
Use "@extend .borders !optional" if the extend should be able to fail.
WARNING on line 54 of /home/git/gitlab/app/assets/stylesheets/sections/notes.scss: "
ul.notes .discussion .discussion-body .discussion-hidden" failed to @extend ".borders".
The selector ".borders" was not found.
This will be an error in future releases of Sass.
Use "@extend .borders !optional" if the extend should be able to fail.
WARNING on line 54 of /home/git/gitlab/app/assets/stylesheets/sections/notes.scss: "
ul.notes .discussion .discussion-body .notes" failed to @extend ".borders".
The selector ".borders" was not found.
This will be an error in future releases of Sass.
Use "@extend .borders !optional" if the extend should be able to fail.
WARNING on line 30 of /home/git/gitlab/app/assets/stylesheets/sections/editor.scss: ".file-editor .commit-button-annotation .commit-btn" failed to @extend ".save-btn".
The selector ".save-btn" was not found.
This will be an error in future releases of Sass.
Use "@extend .save-btn !optional" if the extend should be able to fail.