Frequently Asked Questions

Using Xdebug

Q: phpinfo() reports that Xdebug is installed and enabled, yet I still don't get any stacktraces when an error happens.

A1: You have to search through all your PHP libraries and include files for any "set_error_handler" calls. If there are any, you have to either comment it out, or change the body of the handler function to call xdebug_* api functions.

A2: You do not have set display_errors to 1 in php.ini

Q: The debug client doesn't receive any connections, what do I do wrong?

A: You probably forgot to set the environment variable or to add the necessary information to your URL. See the documentation for more information.

Compilation and Configuration

Q: I'm using XAMPP, but I can't seem to get the packaged xdebug extension to work properly.

A: If you uncommented the "extension=php_xdebug.dll" line, that is to be expected. Xdebug needs to be loaded with the zend_extension_ts= "C:\path\to\php_xdebug.dll" directive. You'll also likely have to disable the loading of the Zend Optimizer, since it's enabled by default, and doesn't work well with Xdebug. So look for the related entry in php.ini, and comment it out.

Q: On Debian, I am seeing the following problem with the build of Xdebug.... any fixes?

/usr/lib/libc_nonshared.a(stat.oS)(.text.__i686.get_pc_thunk.bx+0x0):
In function `__i686.get_pc_thunk.bx':
: multiple definition of `__i686.get_pc_thunk.bx'
/usr/lib/gcc-lib/i486-linux/3.3.5/crtbeginS.o
(.gnu.linkonce.t.__i686.get_pc_thunk.bx+0x0): first defined here
collect2: ld returned 1 exit status
make: *** [xdebug.la] Error 1 

A: This is an issue with Debian itself, see for more information here and here.