Issue building under Windows.

[linsomniac]

I'm trying to get a wheel built for Windows (we run our jobs under Linux and have librets packaged for Ubuntu, but our developers are on Windows), I'm trying to build a github action workflow to build and upload wheels to PyPi for Windows. But during the build I'm running into the following error which I (and various LLMs) are stuck on:

cd c:\librets\vendorsrc\expat\current\expat
	msbuild expat.sln /t:expat;expat_static /p:Configuration=Release /p:Platform=x64
Microsoft (R) Build Engine version 16.11.2+f32259642 for .NET Framework
Copyright (C) Microsoft Corporation. All rights reserved.
Building the projects in this solution one at a time. To enable parallel build, please add the "-m" switch.
Build started 2/26/2025 2:40:12 PM.
Project "c:\librets\vendorsrc\expat\current\expat\expat.sln" on node 1 (expat;expat_static target(s)).
c:\librets\vendorsrc\expat\current\expat\expat.sln.metaproj : error MSB4126: The specified solution configuration "Release|x64" is invalid. Please specify a valid solution configuration using the Configuration and Platform properties (e.g. MSBuild.exe Solution.sln /p:Configuration=Debug /p:Platform="Any CPU") or leave those properties blank to use the default solution configuration. [c:\librets\vendorsrc\expat\current\expat\expat.sln]
Done Building Project "c:\librets\vendorsrc\expat\current\expat\expat.sln" (expat;expat_static target(s)) -- FAILED.
Build FAILED.
"c:\librets\vendorsrc\expat\current\expat\expat.sln" (expat;expat_static target) (1) ->
(ValidateSolutionConfiguration target) -> 
  c:\librets\vendorsrc\expat\current\expat\expat.sln.metaproj : error MSB4126: The specified solution configuration "Release|x64" is invalid. Please specify a valid solution configuration using the Configuration and Platform properties (e.g. MSBuild.exe Solution.sln /p:Configuration=Debug /p:Platform="Any CPU") or leave those properties blank to use the default solution configuration. [c:\librets\vendorsrc\expat\current\expat\expat.sln]
    0 Warning(s)
    1 Error(s)
Time Elapsed 00:00:01.25
NMAKE : fatal error U1077: '"C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\\MSBuild\Current\Bin\msbuild.EXE"' : return code '0x1'
Stop.
Error: Process completed with exit code 1.

My workflow is over here in my fork: https://github.com/linsomniac/libRETS/blob/master/.github/workflows/build_windows_wheels.yml

Any ideas on how I might be able to fix this?