Upcoming Breaking Change: PATH variable update for MSBuild

[mthalman]

Upcoming Breaking Change: PATH variable update for MSBuild

In the August servicing release (Aug 9, 2022), we'll be making a change to the PATH environment variable in all sdk images so that it is set to reference the 64-bit version of MSBuild instead of the 32-bit version. This change to the PATH variable puts it in alignment with the configuration of Visual Studio 2022 which is the intended goal with the sdk images.

We don't anticipate this will cause disruption. If your build works in Visual Studio 2022, it should continue to work in the updated sdk image. In the off-chance of a mis-authored build where a reference is made to a 32-bit-only task but is not described as 32-bit only, then a break may occur. See #971 for more details.

If you'd like to validate your build ahead of time to determine whether it will support this change from 32-bit to 64-bit MSBuild, you can explicitly set the PATH environment variable in your Dockerfile. The example below will cause the 64-bit MSBuild path to take precedence over the 32-bit version:

FROM mcr.microsoft.com/dotnet/framework/sdk:4.8

RUN setx /M PATH "%ProgramFiles(x86)%\Microsoft Visual Studio\2022\BuildTools\MSBuild\Current\Bin\amd64;%PATH%"