OK, it appears that the project previously had a file main.cpp which you apparently renamed to c_main.cpp. The dependencies were generated for the main.cpp file, which is now missing (as a matter of fact, the dependencies for main.cpp are missing - the .deps/main.d file).
There are two solutions for this:
a) Click "Compile/Dist clean" and re-compile, or
b) manually delete the .deps folder inside your project dir and re-compile...
HTH,
Yiannis.