Jammit Error Comiling how to debug?

Anyone seen this before?

2011-04-20T18:45:07+00:00 app[web.1]: Jammit::OutputNotWritable (Jammit doesn't have permission to write to "/app/public/assets"):
2011-04-20T18:45:07+00:00 app[web.1]:   lib/rack/www.rb:7:in `call'
2011-04-20T18:45:07+00:00 app[web.1]: 
2011-04-20T18:45:07+00:00 app[web.1]: 
2011-04-20T18:45:07+00:00 app[web.2]: 
2011-04-20T18:45:07+00:00 app[web.2]: 
2011-04-20T18:45:07+00:00 app[web.2]: Started GET "/assets/beta.js" for 10.249.54.132 at Wed Apr 20 11:45:07 -0700 2011
2011-04-20T18:45:07+00:00 app[web.2]: 
2011-04-20T18:45:07+00:00 app[web.2]: Jammit::OutputNotWritable (Jammit doesn't have permission to write to "/app/public/assets"):
2011-04-20T18:45:07+00:00 app[web.2]:   lib/rack/www.rb:7:in `call'



heroku jammit:deploy
===== Compiling assets.../Library/Ruby/Gems/1.8/gems/closure-compiler-1.0.0/lib/closure/compiler.rb:42:in `compress': stdin:17494: ERROR - Parse error. Internet Explorer has a non-standard intepretation of trailing commas. Arrays will开发者_StackOverflow have the wrong length and objects will not parse at all. (Closure::Error)
};
 ^

1 error(s), 0 warning(s)
    from /Library/Ruby/Gems/1.8/gems/jammit-0.6.0/lib/jammit/compressor.rb:72:in `compress_js'
    from /Library/Ruby/Gems/1.8/gems/jammit-0.6.0/lib/jammit/packager.rb:82:in `pack_javascripts'
    from /Library/Ruby/Gems/1.8/gems/jammit-0.6.0/lib/jammit/packager.rb:40:in `precache_all'
    from /Library/Ruby/Gems/1.8/gems/jammit-0.6.0/lib/jammit/packager.rb:40:in `each'
    from /Library/Ruby/Gems/1.8/gems/jammit-0.6.0/lib/jammit/packager.rb:40:in `precache_all'
    from /Library/Ruby/Gems/1.8/gems/jammit-0.6.0/lib/jammit.rb:124:in `package!'
    from /Library/Ruby/Gems/1.8/gems/jammit-0.6.0/bin/../lib/jammit/command_line.rb:29:in `initialize'
    from /Library/Ruby/Gems/1.8/gems/jammit-0.6.0/bin/jammit:5:in `new'
    from /Library/Ruby/Gems/1.8/gems/jammit-0.6.0/bin/jammit:5
    from /usr/bin/jammit:19:in `load'
    from /usr/bin/jammit:19
[FAIL]

Heroku's filesystem is read only, you will need to upload the compressed stylesheets / javascripts as opposed to running jammit on the server.