在PHP中运行来自EXEC的'git pull'

I'm trying to run a pull request from git using PHP's exec on windows running XAmpp. When running the script below with exec or system and try to access the file the page just never stops loading. I've check the file permissions of the directory and they're all 0777. & running git status runs fine. Not sure what the problem is.

<?php
ignore_user_abort(true);
set_time_limit(15);
exec('git pull origin master', $o);
echo implode("
", $o);
?>

Update there isn't a password on the account:

C:\xampp\htdocs>git pull origin master
From github.com:************
 * branch            master     -> FETCH_HEAD
Already up-to-date.

C:\xampp\htdocs>

Running from terminal i get:

C:\xampp\htdocs>php -f update.php
PHP Warning:  PHP Startup: ming: Unable to initialize module
Module compiled with build ID=API20090626,TS,VC6
PHP    compiled with build ID=API20090626,TS,VC9
These options need to match
 in Unknown on line 0

Warning: PHP Startup: ming: Unable to initialize module
Module compiled with build ID=API20090626,TS,VC6
PHP    compiled with build ID=API20090626,TS,VC9
These options need to match
 in Unknown on line 0
From github.com:*********
 * branch            master     -> FETCH_HEAD
Already up-to-date.
C:\xampp\htdocs>

Instead of using exec, which waits until the process is finished, use passthru and make sure you disabled output buffering. This way you'll immediately see what the problem is.