Following the good advice by @The Shift Exchange I looked at the error_log and indeed managed to solve to problem. it was simply a permissions issue:
Tue Feb 26 11:22:20 2013] [error] [client 127.0.0.1] PHP Fatal error: Uncaught exception 'UnexpectedValueException' with message 'The stream or file "/Users/matanya/Sites/indgo/app/start/../storage/logs/log-apache2handler-2013-02-26.txt" could not be opened: failed to open stream: Permission denied' in /Users/matanya/Sites/indgo/vendor/monolog/monolog/src/Monolog/Handler/StreamHandler.php:71\nStack trace:\n#0 /Users/matanya/Sites/indgo/vendor/monolog/monolog/src/Monolog/Handler/RotatingFileHandler.php(77): Monolog\\Handler\\StreamHandler->write(Array)\n#1 /Users/matanya/Sites/indgo/vendor/monolog/monolog/src/Monolog/Handler/AbstractProcessingHandler.php(37): Monolog\\Handler\\RotatingFileHandler->write(Array)\n#2 /Users/matanya/Sites/indgo/vendor/monolog/monolog/src/Monolog/Logger.php(217): Monolog\\Handler\\AbstractProcessingHandler->handle(Array)\n#3 /Users/matanya/Sites/indgo/vendor/monolog/monolog/src/Monolog/Logger.php(281): Monolog\\Logger->addRecord(400, Object(ErrorException), Array)\n#4 [internal function]: Monolog\\Logger->addError(Object(ErrorException))\n#5 /Users/matanya/Sites/in in /Users/matanya/Sites/indgo/vendor/monolog/monolog/src/Monolog/Handler/StreamHandler.php on line 71
Once I used chmod
to apply less stringent permissions, all went back to normal.
However, I'm not sure that it answers the OP's question, as he was getting a blank screen rather than a server error.