When compiling for Windows it does not properly handle the version string MSB4184

C:\Users\kevin\cpython>PCbuild\build.bat
Using py -3.7 (found 3.7 with py.exe)
Fetching external libraries...
bzip2-1.0.6 already exists, skipping.
sqlite-3.34.0.0 already exists, skipping.
xz-5.2.2 already exists, skipping.
zlib-1.2.11 already exists, skipping.
Fetching external binaries...
libffi already exists, skipping.
openssl-bin-1.1.1i already exists, skipping.
tcltk-8.6.10.0 already exists, skipping.
Finished.
Using "C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\msbuild.exe" (found in the Visual Studio installation)

C:\Users\kevin\cpython>"C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Current\Bin\msbuild.exe" "C:\Users\kevin\cpython\PCbuild\pcbuild.proj" /t:Build /m /nologo /v:m /clp:summary /p:Configuration=Release /p:Platform=x64 /p:IncludeExternals=true /p:IncludeCTypes=true /p:IncludeSSL=true /p:IncludeTkinter=true /p:UseTestMarker= /p:GIT="C:\Program Files\Git\cmd\git.exe"
C:\Users\kevin\cpython\PCbuild\python.props(111,31): error MSB4184: The expression "[System.Version]::Parse('')" cannot
 be evaluated. Version string portion was too short or too long. [C:\Users\kevin\cpython\PCbuild\pythoncore.vcxproj]

Build FAILED.

C:\Users\kevin\cpython\PCbuild\python.props(111,31): error MSB4184: The expression "[System.Version]::Parse('')" cannot
 be evaluated. Version string portion was too short or too long. [C:\Users\kevin\cpython\PCbuild\pythoncore.vcxproj]
    0 Warning(s)
    1 Error(s)

Time Elapsed 00:00:00.06

This should mean that you haven't got the Windows SDK installed, though it might mean that you've got a *newer* WinSDK where they've changed the registration format.

But more likely you deselected it when installing C++ support through Visual Studio. Could you open Visual Studio Installer and ensure that the newest Windows SDK item is selected?

Assuming the spammers go away, we can use this bug to improve the error message. If they persist, we'll lock this and open a new one.

Thank you Steve.  I did not have the latest installed which is Win10SDK_10.0.18362, therefore it did trigger that original error in msg387518.

After installing, Win10SDK_10.0.18362, it did in-fact allow a successful compilation.

Updating that error code would be most helpful to Windows developers.  I would have never caught it but I wanted to help test 3.10 so I thought I should try it on the Windows 10 box to make sure the community had all platforms covered.

RESULTS:
Build succeeded.
    0 Warning(s)
    0 Error(s)

Time Elapsed 00:01:10.34

C:\Users\kevin\cpython>python.bat
Running Release|x64 interpreter...
Python 3.10.0a5+ (heads/master:91a639a094, Feb 22 2021, 14:01:03) [MSC v.1928 64 bit (AMD64)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>>

> I did not have the latest installed which is Win10SDK_10.0.18362, therefore it did trigger that original error in msg387518.

Did you have any other version installed? It should include one by 
default, which is why we don't mention it in the quick instructions, but 
I think you can remove it at install time.

Hi Steve actually there was none installed which was strange as I had Visual Studio installed but it was not checked by default.  After selecting it and installing it, everything works as expected.  Updating the error message in some way might be helpful.

In issue44246, I've encountered this error while attempting to build CPython in a Docker image (built from https://github.com/jaraco/jaraco.windows/blob/d2edad2e2af9d469189d7ac6a14a4ba6f6270348/Dockerfile). Any suggestions on how to install the SDK to a viable version in a headless environment?

Jason - I think your -add and -remove options need work. I'm pretty sure the AzureBuildTools component doesn't bring in the C++ compilers or the WinSDK.

If you configure it manually and interactively, you should be able to export a JSON configuration and then you can use that later to recreate the install elsewhere.

New changeset 80190b3e533097b55077becddc75423318ab2371 by Steve Dower in branch 'main':
bpo-43298: Improved error message when building without the Windows SDK installed (GH-26800)
https://github.com/python/cpython/commit/80190b3e533097b55077becddc75423318ab2371

New changeset 5fbccb763ce540c0d07be86660e0357bffc69d76 by Miss Islington (bot) in branch '3.10':
bpo-43298: Improved error message when building without the Windows SDK installed (GH-26800) (GH-26802)
https://github.com/python/cpython/commit/5fbccb763ce540c0d07be86660e0357bffc69d76

I was able to export the configuration using these instructions: https://docs.microsoft.com/en-us/visualstudio/install/import-export-installation-configurations?view=vs-2019

That produced this config:

{
  "version": "1.0",
  "components": [
    "Microsoft.VisualStudio.Component.CoreEditor",
    "Microsoft.VisualStudio.Workload.CoreEditor",
    "Microsoft.VisualStudio.Component.Roslyn.Compiler",
    "Microsoft.Component.MSBuild",
    "Microsoft.VisualStudio.Component.TextTemplating",
    "Microsoft.VisualStudio.Component.VC.CoreIde",
    "Microsoft.VisualStudio.Component.VC.Tools.x86.x64",
    "Microsoft.VisualStudio.Component.Windows10SDK.19041",
    "Microsoft.VisualStudio.Component.VC.Redist.14.Latest",
    "Microsoft.VisualStudio.ComponentGroup.NativeDesktop.Core",
    "Microsoft.VisualStudio.Workload.NativeDesktop"
  ]
}

Using that, I tried to install those components using vs_buildtools:

# Install Visual Studio
RUN ./vs_buildtools.exe --quiet --wait --norestart --nocache \
 --add Microsoft.VisualStudio.Component.CoreEditor \
 --add Microsoft.VisualStudio.Workload.CoreEditor \
 --add Microsoft.VisualStudio.Component.Roslyn.Compiler \
 --add Microsoft.Component.MSBuild \
 --add Microsoft.VisualStudio.Component.TextTemplating \
 --add Microsoft.VisualStudio.Component.VC.CoreIde \
 --add Microsoft.VisualStudio.Component.VC.Tools.x86.x64 \
 --add Microsoft.VisualStudio.Component.Windows10SDK.19041 \
 --add Microsoft.VisualStudio.Component.VC.Redist.14.Latest \
 --add Microsoft.VisualStudio.ComponentGroup.NativeDesktop.Core \
 --add Microsoft.VisualStudio.Workload.NativeDesktop


In order to avoid noise here, I'm going to continue the investigation in  https://github.com/jaraco/jaraco.windows/issues/21.

New changeset e7009f4f9a6a55036ef628a07bedc8dab1aa851e by Miss Islington (bot) in branch '3.9':
bpo-43298: Improved error message when building without the Windows SDK installed (GH-26800) (#26803)
https://github.com/python/cpython/commit/e7009f4f9a6a55036ef628a07bedc8dab1aa851e