As I found out the IDE is using a tmp folder to store project files, and it obviously uses that folder for compiling files.
Now I had a file named pcTest.cpp. I remaned it to PcTest.cpp, so the previous file pcTest.cpp did not show
in the IDE tabs. In my view pcTest.cpp was just gone. When compiling I ended up with some errors in the
new PcTest.cpp file, fixed them but still got some errors where I did not know where they came from.
After along time trying all kind of things I found out
that the old pcTest.cpp was still present and the IDE compiled both of them.
This is very confusing. As a rule for programming I do not store the same info in different places, that always
causes confusion.
So please remove files when they are not needed any more.