Welcome to the Linux DLL hell!


/* The complete definition of png_info has, as of libpng-1.5.0,
 * been moved into a separate header file that is not accessible to
 * applications.  Read libpng-manual.txt or libpng.3 for more info.
 */
That is why you should always statically link all libararies or use .Net, else some retarded maintainer will break you app "just for fun".

Static linking is a huge space waster and kind of sucks most of the time.
Dynamic linking is great, but you have to be careful on how your libraries are named, loaded, versioned and looked up.