Process.php
public function setEnhanceSigchildCompatibility($enhance)
    {
        @trigger_error(sprintf('The %s() method is deprecated since version 3.3 and will be removed in 4.0. Sigchild compatibility will always be enabled.', __METHOD__), E_USER_DEPRECATED);

        $this->enhanceSigchildCompatibility = (bool) $enhance;

        return $this;
    }
public function setEnhanceSigchildCompatibility($enhance)
    {
        @trigger_error(sprintf('The %s() method is deprecated since version 3.3 and will be removed in 4.0. Sigchild compatibility will always be enabled.', __METHOD__), E_USER_DEPRECATED);

        $this->enhanceSigchildCompatibility = (bool) $enhance;

        return $this;
    }
public function setEnhanceSigchildCompatibility ( $ enhance ) { @ trigger_error ( sprintf ( 'The %s() method is deprecated since version 3.3 and will be removed in 4.0. Sigchild compatibility will always be enabled.' , __METHOD__ ) , E_USER_DEPRECATED ) ; $ this -> enhanceSigchildCompatibility = ( bool ) $ enhance ; return $ this ; }
Activates sigchild compatibility mode.

Sigchild compatibility mode is required to get the exit code and
determine the success of a process when PHP has been compiled with
the --enable-sigchild option

@param bool $enhance

@return self The current Process instance

@deprecated since version 3.3, to be removed in 4.0.
Activates sigchild compatibility mode .