MSVC 2015 builds Failing After 2017 Support added

[Luke Benes]

> The default should be that whatever comes with the compiler should be
> enough, and that installing any separate SDK should be optional.


Agreed, this is how MSVC 2015 worked before the 2017 patch.


> So, if your UCRTVERSION is 10.0.10240.0 (can you verify in
> config_host.mk?), then the corresponding msbuild toolset must be
> installed. Looks like you have only partially installed SDK 10 on your
> machine, so you are on your own.


I have 2 machines that both get this error with the new patch. One of them is a recent, fresh install of Win 10 with only MSVC 2013, 2015 and a few development tools.  There is no partially installed SDK. It's more likely that the detection logic is confused by Win 10.

> Normally we announce something like that on dev ML, or even ask for ESC
> decision. So, no, it wasn't intended. Also note, that all TBs have no
> problems with verification of MSVC 2017 change.

Most of the TBs are running MSVC 2013 which is not affected by this issue. If they are not, I bet they are not running Win 10 or have the SDK installed. I highly doubt there is anything wrong or unusual with either of my systems.

Should I update the wiki to say that Win 10 systems now require the SDK for MSVC 2015? Or is this something that should be fixed?