When using the debugging bundle, fatals errors of php are not displayed in development environment anymore. Instead you just get a blank page (with xdebug) or a 500 error without any concrete info (without xdebug).

This is because the bundle registers its own exception handler that symfony does not expect and thus won't trigger a fatal error exception.

But I'm not sure why the jms exception handler does not kick in then and handle the fatal error. I tried to make the JmsDebuggingBundle exception handler extend the HttpKernel exception handler to get recognised, but that's not so easy because the register methods have different signatures (static vs non-static).