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Xdebug 2.1

I've just released Xdebug 2.1. This new release contains all the bug fixes and new features that have been developed over the past three years. It provides full PHP 5.3 support, but it no longer supports PHP versions below 5.1.

A description of all the new features follows:

Error Collection

I've added xdebug_start_error_collection(), xdebug_stop_error_collection() and xdebug_get_collected_errors(), which allow you to collect all notices, warnings and error messages that Xdebug generates from PHP's error_reporting functionality so that you can output them at a later point in your script by hand.

Header Setting Interception

All functions that set HTTP headers such as with header() and setcookie() are now intercepted by Xdebug. The intercepted headers are stored internally in an array that can be retrieved by calling the xdebug_get_headers() function. This is very useful in cases where you need to test certain functionality that sets headers somewhere deep in code. This function is also used in eZ Components' test suite to test whether the correct HTTP headers are set in the MvcTools component.

Variable Assignment Tracing

The new setting xdebug.collect_assignments allows you to record changes to variables in scripts to trace files. I've already written more about it in Variable tracing with Xdebug.

"Scream" Support

The scream PECL extension disables the @ (shut-up) operator to actually see all notices, warnings and errors that PHP generates. The scream extension's functionality have been duplicated as Xdebug's xdebug.scream php.ini setting. Why disabling the @-operator is a good thing, I've already outlined in Five reasons why the shut-op operator (@) should be avoided.

Additions for Stack Traces

All HTML containers generated by Xdebug (error messages, xdebug_var_dump() output) now contain a CSS class for easier styling.

The new setting xdebug.file_link_format allows you to turn any file/line link in Xdebug's output to be decorated to a link with a specific format. For example you can set it to txmt://open/?file://%f&line=%l for opening files directly in Textmate, or gvim://%f@%l with some shell script for gvim and Firefox.

Remote Debugging

The new setting xdebug.remote_connect_back, contributed by Lucas Nealan and Brian Shire, allows Xdebug to try to make a debugging connection to the IP address from which the browser request came from. This setting is an additional solution for debugging with multiple users.

The old gdb and php3 remote debugging engines have been removed.

Overloaded var_dump

The newly introduced setting xdebug.overload_var_dump can be used to turn off Xdebug's default behavior of overriding PHP's var_dump() function with the xdebug_var_dump() function that uses pretty HTML for formatting a variable structure. It does not stop xdebug_var_dump() from working however.


You can probably imagine that writing and support Xdebug is a time-consuming effort. It's a tool that saves a lot of work during developement of applications, as well while debugging. If you think Xdebug is valuable for you, perhaps you would like to consider a donation. All donations are greatly appreciated and support future development and availablity of Xdebug.

If you want to sponsor a (new) feature in Xdebug, feel free to contact me as well.

Download and Support

The new version of Xdebug can be downloaded through the download page. A list with all changes can be found on the updates page. Support information can be found on the support page, and issues and feature requests can be filed in the bug tracker. Before asking for support, please have a look at the FAQ first.


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Thanks Derick for this great software, the header/cookie interception could be very interesting.


Simply awesome!


Wow, great new stuff! Thanks!

A critical tool in the PHP ecosystem. Thanks for all your work


Just wondering how compatible this is with zend studio debugger? As that is what we're currently using within our development office.

It would be very nice to have both xdebug and zend debugger installed alongside each other.

I know you wrote a patch file for it (, but that was for version 2.0.3? Would the patch still be applicable to this latest release?

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