I run an apache-server and I need just one php_flag to differ from the global configuration in a virtual host.
I did not have a .htaccess file in that virtual hosts
php_flag can only set PHP_INI_ALL and PHP_INI_PERDIR type directives. You may need to use a php_admin_flag within a <Directory xxxxxxxxxx> </Directory> scope in your vhost config. You will need to restart Apache to latch this.
php_flag
php_admin_flag
<Directory xxxxxxxxxx>
</Directory>