How to analyze coverage:
1. read CONTRIBUTING.md file.
2. gbs build adding --define '_with_coverage 1'
3. take *.o and *.gcno files from compilation (<gbs-build-root>/home/abuild/rpmbuild/BUILD/dbus-1.10.6/dbus/.libs) into a /safe/place
	you may also use generated rpm package dbus-coverage-objects.
4. install coverage package (dbus-coverage) on the target
5. run test programs adding LD_LIBRARY_PATH=/usr/lib/dbus-tests/coverage-libs
	Data gathering is cumulative, so you can run multiple programs one after another.
	Use GCOV_PREFIX and GCOV_PREFIX_STRIP environment variables to set output directory.
	If not set, data files (*.gcda) will be generated in /home/abuild/rpmbuild/BUILD/dbus-1.10.6
6. download generated gcda files from the target to /safe/place
7. put source code *.c files together with object files into a /safe/place
8. run gcov /safe/place/*.o
	or gcov -r /safe/place/*.o for only local source code output