Five years ago the OP's problem was that the PRO file was self-referential. The first time qmake ran it generated a Makefile for the subdirs template and then recursed into each subdir and repeated the process. Problem was that the 'subdir' referred tot the same PRO file again. Eventually this would terminate, leaving the multitude of Makefiles described. Running make at that time would look to see if qmake needed to be run, decide it did not, and produce the nothing to do message. At no time did the OP's PRO file include the C++ sources... Jacek, jpn and dangdude all showed what was wrong.