Due to asset pipelining, app/assets/images/blacktocat.png cannot be referenced in the css with its relative path inside stylesheet.css. As a result, the blacktocat.png image is now omitted and replaced by the background rule of custom.css.
As soon as I get hold of how asset pipelining actually works, I will make a pull request for fixing the specific issue.
Due to asset pipelining, app/assets/images/blacktocat.png cannot be referenced in the css with its relative path inside stylesheet.css. As a result, the blacktocat.png image is now omitted and replaced by the background rule of custom.css.
As soon as I get hold of how asset pipelining actually works, I will make a pull request for fixing the specific issue.