windows/msvc/paths.props: Dont add variant path for mpy-cross build.

jimmo · jimmo · commit 8f4a6d502411 · 2023-06-06T23:10:05.000+10:00
This file is shared by mpy-cross.vcxproj, where PyVariant will be not set
(because common.props explicitly doesn't set it when building mpy-cross).

However, paths.props will attempt to default PyVariantDir to
`variants\$(PyVariant)\` which will end up as `variants\\` and the double
backslash breaks the cl.exe command line.

So this also ensures that PyVariant is set before defaulting PyVariantDir.

This work was funded through GitHub Sponsors.

Signed-off-by: Jim Mussared &lt;jim.mussared@gmail.com&gt;
diff --git a/ports/windows/msvc/paths.props b/ports/windows/msvc/paths.props
@@ -28,7 +28,7 @@
     <PyBaseDir>$([System.IO.Path]::GetFullPath(`$(MSBuildThisFileDirectory)..\..\..`))\</PyBaseDir>
     <PyWinDir>$(PyBaseDir)ports\windows\</PyWinDir>
     <PyBuildDir Condition="'$(PyBuildDir)' == ''">$(PyWinDir)$(PyBuild)\</PyBuildDir>
-    <PyVariantDir Condition="'$(PyVariantDir)' == ''">$(PyWinDir)variants\$(PyVariant)\</PyVariantDir>
+    <PyVariantDir Condition="'$(PyVariantDir)' == '' and '$(PyVariant)' != ''">$(PyWinDir)variants\$(PyVariant)\</PyVariantDir>
     <PyTargetDir Condition="'$(PyTargetDir)' == ''">$(PyBuildDir)</PyTargetDir>
 
     <!-- All include directories needed for uPy -->
