How to test an EXE with Google Test? (2)

I modified one of the answers here like

std::string path_to_exectuable = "thepath";
TEST(FooTester,CheckHelpScriptReturns0)
{
 using bp =::boost::process; 
 std::vector<std::string> args; args.push_back("--help");
 bp::context ctx; 
 ctx.stdout_behavior = bp::capture_stream(); 

 bp::child c = bp::launch(exec, args, ctx); 
 EXPECT_EXIT(c.terminate(), ::testing::ExitedWithCode(0), "");
}

in the hope to make it more straightforward. However, this wont work,and will output

Result: failed to die

So, is this approach possible at all, and if yes, what is missing?