its target source and edit it
What I gather from the screenshot is that one of the test cases has failed. If it's the first time you are building the project, perhaps it is because the master was broken when you last pulled from repository, in that case do 'git pull -r' and then 'make' again.
If you've already build before and this is happening after you made certain modifications, you can run:
make CppunitTest_sal_osl_security CPPUNITTRACE=TRUE
to get the stack trace and what is going wrong and where.
This is just what I gather from the screenshot. I've never used Visual Studio, not am an expert in this. Most of the developers won't be available during weekends, so I suggest you wait a couple of days for them to respond.