Source Mapping in Coffeescript - errors not mapped to source
I actually just answered my own question very similar to yours. You can take a look here.
The solution I am using is to concat/compile all my coffeescript with browserify,using coffeeify as a transform option. When debug is set to true in browserify, all your line numbers should map back to the correct line in your original coffeescript source.
I found that the problem only occurs on the initial opening of the Chrome console.
If you refresh the browser while the console is open, the console will update with links to the source-mapped files.
Also, if you open the console first and then navigate to the page, the console will update with links to the source mapped files.
This is an issue associated with Chrome opening the console for the first time.