The problem described below was resolved by changing the Pipeline yaml. The Build.proj that was included had incorrect parameters. It was pilot error.
I have a VisualStudio 2017 solution which builds in VS, when I push the Branch to merge with a Microsoft Hosted Azure DevOps Git master, the pipeline fails saying Platform Toolset = v150 cannot be found. I cannot find Platform Toolset v150 anywhere.
The Platform Toolset used when it successfully builds on VS2017 is v141, and is v142 on VS2019. It builds as Release x64 on both VS2017 and 2019. Since v150 does not exist, I assume that this is some sort of unexplained error condition. I don't know where to look for better clues about what failed.
Here is the error: ##[error]C:\Program Files (x86)\Microsoft Visual Studio\2017\Enterprise\Common7\IDE\VC\VCTargets\Microsoft.Cpp.Platform.targets(67,5): Error MSB8020: The build tools for v150 (Platform Toolset = 'v150') cannot be found. To build using the v150 build tools, please install v150 build tools. Alternatively, you may upgrade to the current Visual Studio tools by selecting the Project menu or right-click the solution, and then selecting "Retarget solution". [D:\a\1\s\xxxxxxxxxxxxxxx.vcxproj]
I have also run the build from the command line as:
"%ProgramFiles(x86)%\Microsoft Visual Studio\2017\Enterprise\MSBuild\15.0\Bin\msbuild.exe" build.proj /t:Build /verbosity:normal /fileLogger /fileloggerparameters:Append
and see the same "v150 cannot be found" error