Php error when using xdebug

Next, if there is an error in php error log

symbol search error: /usr/local/php5/extensions/xdebug.so: undefined symbol: php_get_module_initialized

And with this error, I cannot use debug mode for php with apache. Since if the mysql code has an error, the Browser shows a blank page but not an error page to tell me what is going on.

Has anyone seen this error?