Building and accessing on VPS

I have a PHP application that is trying to use OAuth to access Autodesk’s servers. It fails with this error:

Fatal error: Class ‘OAuth’ not found in file.php on line 56

because it can’t find the class definition for the OAuth class.

I was told I needed to convert from my shared hosting account to a VPS and install liboauth-php so it can build the library which contains the OAuth class definitions, that this program references. I understand that once built I can reference the extension file from my phprc file.

I used aptitude install liboauth-php to install the liboauth-php library, but the shared object file was not created and installed anywhere on the server.

What’s wrong? I could reference the extension in my phprc file – if only I could find it. And how do I get this the shared object built?