I'm getting a large number of undefined references when using

$ld xdebug.so

I have added the "zend_extension="/bla/xdebug.so"" to the conf for apache and it is giving me a config test failed because it cannot find the file. The file has been chown'd to www-data, so I do not believe it is a permissions error. I have run the wizard at xdebug.org/wizard.php to make sure the version would be correct, I updated to the version it recommended with an install from source and still receive the same error with apache and same output from $ld. I originally installed xdebug with:

$apt-get install php5-xdebug

And have also tried with:

$pecl install xdebug