Changing BaseIntermediateOutputPath causes build error CS0103

I have a simple .net standard project that included Xamarin.Forms in Visual studio 2017. The build was successful until I change the default BaseIntermediateOutputPath in project file.

Snippet of the .csproj file:

<PropertyGroup>
    <TargetFramework>netstandard1.4</TargetFramework>
    <PackageTargetFallback>portable-net45+win8+wpa81+wp8</PackageTargetFallback>
    <BaseIntermediateOutputPath>hello/</BaseIntermediateOutputPath>   <!-- Comment this out and build passes -->
</PropertyGroup>

The build error was:

Page1.xaml.cs(17,4): error CS0103: The name 'InitializeComponent' does not exist in the current context.

After inspecting the msbuild output. It looks like the XamlG target never included/executed.

Any insight?

Thanks.

C.