OrchardCore doesn't work on net6.0

[eerhardt]

Describe the bug

When trying to use OrchardCore on a net6.0 app, the default page 404s.

To Reproduce

1. Build and run the following app using the latest 6.0.0-preview7 build:

<Project Sdk="Microsoft.NET.Sdk.Web">
  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="OrchardCore.Application.Cms.Targets" Version="1.0.0-rc2-13450" />
  </ItemGroup>
</Project>

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;

Host.CreateDefaultBuilder(args).ConfigureWebHostDefaults(webbuilder =>
{
    webbuilder.Configure(app =>
    {
        app.UseRouting();

        app.UseStaticFiles();

        app.UseOrchardCore();

    });
})
.ConfigureServices(services => { services.AddOrchardCms(); })
.Build()
.Run();

2. Navigate to https://localhost:5001/

Exceptions (if any)

(Note: there is a background NullReferenceException occurring in DependencyInjection code. That is tracked by dotnet/runtime#55255. I've fixed it locally and ensured that this issue still occurs even when the NRE is fixed.)

Further technical details

• ASP.NET Core version: 6.0.0-preview.7.21355.4
• Include the output of dotnet --info

❯ dotnet --info
.NET SDK (reflecting any global.json):
 Version:   6.0.100-preview.7.21357.29
 Commit:    229bc924ef

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.19043
 OS Platform: Windows
 RID:         win10-x64
 Base Path:   C:\dotnet\sdk\6.0.100-preview.7.21357.29\

Host (useful for support):
  Version: 6.0.0-preview.7.21356.2
  Commit:  566b53a66b

.NET SDKs installed:
  6.0.100-preview.7.21357.29 [C:\dotnet\sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 6.0.0-preview.7.21355.4 [C:\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 6.0.0-preview.7.21356.2 [C:\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 6.0.0-preview.7.21352.1 [C:\dotnet\shared\Microsoft.WindowsDesktop.App]

To install additional .NET runtimes or SDKs:
  https://aka.ms/dotnet-download

• The IDE (VS / VS Code/ VS4Mac) you're running on, and its version: n/a

cc @davidfowl

[adityamandaleeka]

I was able to repro this. Dropping some logged info here in case it's helpful later...

trce: Microsoft.AspNetCore.Server.Kestrel.Http2[37]
      Connection id "0HMA2FMPU9JHK" received HEADERS frame for stream ID 25 with length 22 and flags END_STREAM, END_HEADERS, PRIORITY.
info: Microsoft.AspNetCore.Hosting.Diagnostics[1]
      Request starting HTTP/2 GET https://localhost:5001/ - -
trce: Microsoft.AspNetCore.HostFiltering.HostFilteringMiddleware[2]
      All hosts are allowed.
dbug: Microsoft.AspNetCore.Routing.Matching.DfaMatcher[1000]
      No candidates found for the request path '/'
dbug: Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware[2]
      Request did not match any endpoints
dbug: Microsoft.AspNetCore.StaticFiles.StaticFileMiddleware[4]
      The request path / does not match a supported file type
info: OrchardCore.Modules.ModularTenantRouterMiddleware[0]
      Begin Routing Request
dbug: Microsoft.AspNetCore.Routing.Matching.DfaMatcher[1000]
      No candidates found for the request path '/'
dbug: Microsoft.AspNetCore.Routing.EndpointRoutingMiddleware[2]
      Request did not match any endpoints
dbug: Microsoft.AspNetCore.StaticFiles.StaticFileMiddleware[4]
      The request path / does not match a supported file type
trce: Microsoft.AspNetCore.Server.Kestrel.Http2[49]
      Connection id "0HMA2FMPU9JHK" sending HEADERS frame for stream ID 25 with length 38 and flags END_STREAM, END_HEADERS.
info: Microsoft.AspNetCore.Hosting.Diagnostics[2]
      Request finished HTTP/2 GET https://localhost:5001/ - - - 404 0 - 0.4202ms

[davidfowl]

@pranavkm @javiercn I haven't dug in here enough yet but it might be an MVC or routing problem.

[javiercn]

@davidfowl there are two things that I can think about being problematic here:

• Application parts
• The call to UseEndpoints, which I don't get to see anywhere

I was expecting to see an app.UseEndpoints(endpoints => endpoints.MapControllers())

Not sure if app.UseOrchardCore(); is doing it internally, but if so, it should not. We provide explicit guidance to customers not to subsume UseRouting and UseEndpoints within their own extension methods.

[davidfowl]

Yea, but it used to work in .NET 5, this is a compat break in .NET 6. We need to figure out why it broke

[davidfowl]

UseOrchardCore is doing it internally. Along with alot of other crazy things 😄

[javiercn]

@davidfowl my money is on application parts not working well with top-level statements or some of the new minimal hosting APIs, that's what I would check first.

Does it work outside of orchard?

[davidfowl]

Top level statements? Yes.