use CPPUNITTRACE now and explain how to use with visual studio

Change-Id: Ic8a76ac6eb96fe82707512ad8e00fef8309111ef

solenv/gbuild/CppunitTest.mk

@@ -23,13 +23,13 @@
 # $(1): "Cppunit" or "Python"
 # $(2): the name of the unit test that failed
 define gb_UNIT_FAILED_MSG
-printf '\nError: a unit test failed, please do one of:\n\nexport DEBUGCPPUNIT=TRUE            # for exception catching\nexport GDBCPPUNITTRACE="gdb --args" # for interactive debugging\nexport VALGRIND=memcheck            # for memory checking\n\nand retry using: make %sTest_%s\n\n' $(1) $(2)
+printf '\nError: a unit test failed, please do one of:\n\nexport DEBUGCPPUNIT=TRUE            # for exception catching\nexport CPPUNITTRACE="gdb --args" # for interactive debugging on linux\nexport CPPUNITTRACE="\"[full path to devenv.exe]\" /debugexe" # for interactive debugging in Visual Studio\nexport VALGRIND=memcheck            # for memory checking\n\nand retry using: make %sTest_%s\n\n' $(1) $(2)
 endef
 
 ifeq ($(strip $(DEBUGCPPUNIT)),TRUE)
 gb_CppunitTest_GDBTRACE := gdb -nx -ex "add-auto-load-safe-path $(OUTDIR)/lib" --command=$(SOLARENV)/bin/gdbtrycatchtrace-stdout -return-child-result --args
-else ifneq ($(strip $(GDBCPPUNITTRACE)),)
-gb_CppunitTest_GDBTRACE := $(GDBCPPUNITTRACE)
+else ifneq ($(strip $(CPPUNITTRACE)),)
+gb_CppunitTest_GDBTRACE := $(CPPUNITTRACE)
 gb_CppunitTest__interactive := $(true)
 endif