Mono's msbuild can't build Blazor WASM projects #19466
Description
Steps to Reproduce
$ dotnet new -i Microsoft.AspNetCore.Components.WebAssembly.Templates::3.2.0-preview3.20168.3
$ dotnet new blazorwasm -o Wasm
$ cd Wasm
$ msbuild Wasm.csproj
Current Behavior
Build fails with:
_ResolveBlazorInputs:
Creating directory "obj/Debug/netstandard2.1/blazor/".
/Users/rodrigo/.nuget/packages/microsoft.aspnetcore.components.webassembly.build/3.2.0-preview3.20168.3/targets/Blazor.MonoRuntime.targets(348,5): error : Specified cast is not valid. [/private/tmp/BlazorWasm/BlazorWasm.csproj]
Done Building Project "/private/tmp/BlazorWasm/BlazorWasm.csproj" (default targets) -- FAILED.
Expected Behavior
Build succeeds
On which platforms did you notice this
[x] macOS
[ ] Linux
[ ] Windows
Version Used:
6.10.0.101
Stacktrace
See dotnet/aspnetcore#20259 for more information and the MSBuild stack trace. From the last comment from @pranavkm seems the issue is with the DataContractJsonSerializer implementation in Mono