The problem arises because google coders are relying on the fact that the C++ standard allows you to treat an undefined preprocessor symbol as evaluating to 0. There is a bunch of #if directives that test the value of PROTOBUF_INLINE_NOT_IN_HEADERS when it hasn’t been defined anywhere.
So to fix this, you should add this line in the CMakeList.txt that you find in the opentxs main folder :
SConstruct and CXXFLAGS in src/SConscript (CXXFLAGS) and that seemed to catch it.
And don't forget to repeat the CMake step.