ASP.NET's global.json `tool\vs` section behaves poorly

[ericstj]

I was running into a situation where I my ASP.NET build was consistently failing to find FSharp targets when building.

aspnetcore/global.json

Lines 16 to 22 in 9a6b2eb

	"version": "17.13",
	"components": [
	"Microsoft.VisualStudio.Component.VC.ATL",
	"Microsoft.VisualStudio.Component.VC.ATL.ARM64",
	"Microsoft.VisualStudio.Component.VC.Tools.ARM64",
	"Microsoft.VisualStudio.Component.VC.Tools.x86.x64"
	]

I found the root cause was my devbox (VS Client SKU) had VC, ATL, x64 and ARM64 tools. I was missing ARM64 ATL libs - apparently wasn't part of the workflows installed.

The result was that ASPNETCore build decided to not use my installed VS, but instead decided to download the Xcopy-MSBuild package, which not only was missing all the VC components but also missing FSharp targets 🙃

Seems this isn't working as expected....