symfony2 error when executing doctrine:generate:entity command

Question

The Entity shortcut name [AcmeDemoBundle:User]: Notice: Undefined variable: output in /opt/case/symfony/Symfony/vendor/symfony/symfony/src/Symfony/Component/Console/Helper/DialogHelper.php line 411

Report this error, why? If you execute the command directly after downloading, the environment is ubuntu+php5.3.18+nginx. Please fix it!

Answer 1

Notice: Undefined variable: output
The output variable is undefined. Check the source code

Answer 2

Search disable_function in php.ini configuration

Yours may look like this

disable_functions =exec,passthru,shell_exec,system,proc_open

You want to delete it

exec, shell_exec