Suppose that libraries are located in the same directory as an application.
If we start the application then it fails with message that library not found.
The simplest way to solve this is to add "." to $LD_LIBRARY_PATH.
The better approach is to specify linker flag -Wl,-rpath,'$ORIGIN' in Makefile (for LFLAGS).
The question: How to add the flag to Makefile using *.pro file? I cannot understand what characters should be escaped and how to do this.