Building Panda3D with MSVC 2015 and Python 3.5/3.6

composite2.obj doesn’t tell me anything; that’s not the complete file. I suspect it’s merely a big file, though, so I would suggest you wait.

You could use --no-eigen in the compilation flags to get a significantly faster build. You should also use --threads 2 (or as many cores as you can spare) to significantly speed up the build.