Description of problem:
I trie to build qt from sources
Used call_configure function from build_script.sh resets LD_LIBRARY_PATH with 
own value. But this can hurt non-standart system functioning that uses 
LD_LIBRARY_PATH to point for some needed libraries (for example custom 
compiler, or some checkers, wrappers, etc). With voilating LD_LIBRARY_PATH 
system might stop functioning properly and build of qt shall fail. So got I. I use 
LD_LIBRARY_PATH for pointing on compiler libraries therefore with resetting 
LD_LIBRARY_PATH by call_configure my compiler stops working. Please change 
build_script.sh not to overwrite LD_LIBRARY_PATH but add to it, that would only 
increase Red Hat Linux portability.
I'll attach the patch which does this change.

Version-Release number of selected component (if applicable):


How reproducible:
always on LD_LIBRARY_PATH dependent system

Steps to Reproduce:
1. I am unsure you will get that error, but you may try to build qt by custom C/C++ 
compiler, for example by elder version of gcc, installing it to local directory with 
using LD_LIBRARY_PATH for pointing the path where its libraries lies. Or you 
may use Intel C/C++ compile for that, as I know it uses LD_LIBRARY_PATH.
    
Actual results:
Configuration error as compiler cannot work in changed environment

Expected results:
Succesfully built qt.

Additional info: