Add a prompt in toolchain.lua for the user to run vcvarsall.bat if their WindowsSDKVersion env var is not set. Don't make 8.1 the default value.
We could do this properly by inspecting registry values but from what I remember this is incredibly fiddly to get right across the different versions, so might be easiest to rely on vcvarsall.bat for now
Add a prompt in toolchain.lua for the user to run vcvarsall.bat if their WindowsSDKVersion env var is not set. Don't make 8.1 the default value.
We could do this properly by inspecting registry values but from what I remember this is incredibly fiddly to get right across the different versions, so might be easiest to rely on vcvarsall.bat for now