Hello. Yes, there have always been a lot of issues when trying to compile the libgmic with Microsoft Visual Studio.
Particularly, when the optimizations are enabled (so in Release mode), this takes forever to complete (several hours).
Don't ask me why, I suspect this is a problem with the compiler itself
I haven't made a lot of tests, so I can't say much about that. What I did is compiling the libgmic in Debug mode, and without any dependencies activated, so something pretty useless at the end, but it was done mainly to see if there was compiler warnings or errors that I could fix.
Sorry for this non-answer by the way