Deployed PHP application works just fine on three of those machines and fails totally with the following error:
PHP Fatal error: Uncaught Error: Call to undefined function apache_setenv() in ...
Can someone explain to me, how in the heaven this is possible?
This runs beyond my imagination. My experience tells me that if I have used exactly the same installer (meaning that my PHP on all four machines is compiled by the same person based on the same sources and configuration) then it is simple impossible that such installation reports missing PHP extension on only one of four deployment targets.
Furthermore, is there anything I can do about this? Can I somehow add / enable ext-apache extension in my PHP and make my application running on all targets?