I do not want to disable xdebug when I am developing. Just wanted to confirm that running xdebug in dev environment should have no impact on the composer installing libraries/performance of the app on the production server.
There is a huge impact of just loading Xdebug. It slows the Composer run down by 3x or 4x, even when the profiling feature is not enabled.
In other words: xdebug is invaluable for debugging, but increases the memory used and processing time of Composer.
How to disable Xdebug for Composer runs?
My suggestion is to write a little invocation helper for running Composer.
The helper is a bash or batch script calling PHP with a custom php.ini, especially configured for Composer. Lets call it: php.ini-composer.
You could copy your current php.ini and adjust it for the Composer run, by removing xdebug or commenting it out, like so: ;zend_extension = "/path/to/my/xdebug.so".
While you are at it: setting memory_limit=-1 is helpful, too.
The full command looks like so on Windows: php.exe -c php.ini-composer composer.phar %*
Just clone the idea for a bash script.
And you may find the full answer to your question in the Composer FAQ.
https://getcomposer.org/doc/articles/troubleshooting.md#xdebug-impact-on-composer
It was added/updated just a few hours ago.
Some alternatives (instead of using seperate ini file) are also mentioned here.
