Xamarin: How do you set a breakpoint in a simple C++ project?

I am new to Xamarin Studio. I am trying to set a breakpoint in a C++ project's automatically created main.cpp file, which contains a hello world line only. I am on Xamarin Studio Community 5.10.3 (build 51) on Mac. The solution is created from a template in Other->Miscellaneous->C/C++->Console Project->CPP. While debugging I am setting a breakpoint but execution won't stop at the breakpoint. How to make the debugger to stop there?