Hello.
I am trying to build VCMI from source on Linux. However, build fails (both on git master and 0.98):
/home/stuff/src/vcmi/lib/CArtHandler.cpp: In member function 'boost::optional<std::vector<CArtifact*>&> CArtHandler::listFromClass(CArtifact::EartClass)':
/home/stuff/src/vcmi/lib/CArtHandler.cpp:674:10: error: could not convert 'nullptr' from 'std::nullptr_t' to 'boost::optional<std::vector<CArtifact*>&>'
return nullptr;
^