title: ExecJS::ProgramError: Unexpected token punc «(», expected punc «:» when running rake assets:precompile on production
body: <p>When deploying my Rails app I get the following error:</p>
  
  <pre><code>rake aborted!
     ExecJS::ProgramError: Unexpected token punc «(», expected punc «:» (line: 15, col: 14, pos: 265)
  
     Error
     at new JS_Parse_Error (/tmp/execjs20150524-4411-1p45n63js:2359:10623)
     at js_error (/tmp/execjs20150524-4411-1p45n63js:2359:10842)
     at croak (/tmp/execjs20150524-4411-1p45n63js:2359:19086)
     at token_error (/tmp/execjs20150524-4411-1p45n63js:2359:19223)
     at expect_token (/tmp/execjs20150524-4411-1p45n63js:2359:19446)
     at expect (/tmp/execjs20150524-4411-1p45n63js:2359:19584)
     at /tmp/execjs20150524-4411-1p45n63js:2359:28513
     at /tmp/execjs20150524-4411-1p45n63js:2359:19957
     at expr_atom (/tmp/execjs20150524-4411-1p45n63js:2359:27269)
     at maybe_unary (/tmp/execjs20150524-4411-1p45n63js:2359:30019)new JS_Parse_Error ((execjs):2359:10623)
     js_error ((execjs):2359:10842)
     croak ((execjs):2359:19086)
     token_error ((execjs):2359:19223)
     expect_token ((execjs):2359:19446)
     expect ((execjs):2359:19584)
     (execjs):2359:28513
     (execjs):2359:19957
     expr_atom ((execjs):2359:27269)
     maybe_unary ((execjs):2359:30019)
  </code></pre>
  
  <p>The file in question is valid, it works on localhost. I also tried running <code>rake assests:precompile</code> on localhost, it all passes. Finally, I tried to remove the content from the file, git push and redeploy - still got the same error. Only completely removing the file and re-deploying helps.</p>
  
  <p>Would appreciate any ideas.</p>