cache or why symfony stops running

Installing a new plugin left me with the command line of symfony does nothing.
steps i've made to try and tackle the problem were checking the php_error.log inside MAMP if you go to main folder of MAMP it's under logs (there's an article explaining how to have the error logs as a widget when clicking F4, how to have it.
the symfony file itself is a batch file, so you can try and debug the file, i just use echo to print in the terminal.
well the errors i got aren't very helpful, so last resort i decided after spending quite a while is to delete the cache. 
in the project folder one of the folders is cache. i renamed it and created a new cache folder. i suspect the project_autoload.cache file caused the problem.
although running the dev env should omit the cahce it didn't reach that point in the code :-(