Is it possible to comment out this line in the new app/assets/application.js file? If so, how?
//=require jquery_ujs
I mean, it's already commented out to avoid being misconstrued as CoffeeScript or JavaScript, but it's obviously serving a purpose still.
Taken from the Sprockets 1.02 github (Sprockets 2 is what rails 3.1 uses to accomplish asset loading):
How Sprockets handles comments
Use single-line (//) comments in JavaScript source files for comments that don't need to appear in the resulting concatenated output.Use multiple-line (/* ... */) comments for comments that should appear in the resulting concatenated output, like copyright notices or descriptive headers. PDoc (/** ... **/) documentation comments will not be included in the resulting concatenation.
Comments beginning with //= are treated by Sprockets as directives. Sprockets currently understands two directives, require and provide.
What this means is that //= jquery_ujs is a directive. It instructs Sprockets to include the jquery_uls file when it compiles all the jquery files.
If you don't want that file included, just remove the equals sign and the directive becomes a comment.