We have a standalone application which uses ROOT and the TMVA library, which we can compile and link successfully on linux (RHEL4 gcc 3.4) but not on windows (VC++ 7.1). The resulting error is:
unresolved external symbol "private: static class TMVA::Config* TMVA::Config::fgConfigPtr
We typically compile ROOT ourselves - I receive this error when using ROOT 5.20.00. I also downloaded the binary distribution of v5.24.00 and got the same result.
This is a problem with TMVA under Windows. I have now fixed the problem in the SVN trunk.
Because on Windows an inline function cannot get or access a global variable
the two following functions have been moved to the implementation file.
static Config& Instance();
static void DestroyInstance();
with the following implementation: