I strongly suggest you don't go adding directories to the library path, thats a very Windows way to think. In Unix, libraries are shared and exist in agree places.
You can find debs and rpms that install libqt5pas and the dev library too at
https://github.com/davidbannon/libqt5pas/releasesIf you want/need to specifically build your own, maybe with some changes ? then look on your own system and see where similar libraries live. Put your new ones there too. The convention is for the build library to have its full name and version number and then symlink to name and simplified version number.
Sometimes, really obsessive sysadmins will give the built library a name like -
hand-built-libQt5Pas.so.1.2.10 -- actual binary
libQt5Pas.so.1.2.10 -- symlink to above
libQt5Pas.so.1 -- symlink to above
libQt5Pas.so -- symlink to above
For my interest sake, just what distro are you using ?
EDIT : do not confuse run time paths to libraries with compile and link time paths to libraries.
Davo