Assembly probing not working as expected in .NET 6.0 Preview 6

[brettsam]

I'm on the Azure Functions team and as I moved us forward to preview 5, we started getting this in our CI build while running tests:

System.IO.FileNotFoundException: 'Could not load file or assembly 'Grpc.Core.Api, Version=2.0.0.0, Culture=neutral, PublicKeyToken=d754f35622e28bad'. The system cannot find the file specified.'

I'm able to repro this locally. When I switch back to preview 4, it goes away.

I enabled CORHOST_TRACE to see what looked different and here's what I see when I look for Grpc.Core.Api:

in Preview 4

Processing TPA for deps entry [Grpc.Core.Api, 2.38.1, lib/netstandard2.0/Grpc.Core.Api.dll]
  Considering entry [Grpc.Core.Api/2.38.1/lib/netstandard2.0/Grpc.Core.Api.dll], probe dir [], probe fx level:0, entry fx level:0
    Local path query did not exist C:\git\dotnet_6\azure-functions-host\test\WebJobs.Script.Tests\bin\Debug\net6.0\Grpc.Core.Api.dll
    Skipping... not found in deps dir 'C:\git\dotnet_6\azure-functions-host\test\WebJobs.Script.Tests\bin\Debug\net6.0\'
    Skipping... not found in probe dir ''
  Considering entry [Grpc.Core.Api/2.38.1/lib/netstandard2.0/Grpc.Core.Api.dll], probe dir [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App\6.0.0-preview.4.21253.5], probe fx level:1, entry fx level:0
    Skipping... not found in deps json.
    Skipping... not found in probe dir 'C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App\6.0.0-preview.4.21253.5'
  Considering entry [Grpc.Core.Api/2.38.1/lib/netstandard2.0/Grpc.Core.Api.dll], probe dir [C:\Program Files\dotnet\shared\Microsoft.NETCore.App\6.0.0-preview.4.21253.7], probe fx level:2, entry fx level:0
    Skipping... not found in deps json.
    Skipping... not found in probe dir 'C:\Program Files\dotnet\shared\Microsoft.NETCore.App\6.0.0-preview.4.21253.7'
  Considering entry [Grpc.Core.Api/2.38.1/lib/netstandard2.0/Grpc.Core.Api.dll], probe dir [C:\Users\brettsam\.nuget\packages], probe fx level:-1, entry fx level:0
    Relative path query exists C:\Users\brettsam\.nuget\packages\grpc.core.api\2.38.1\lib\netstandard2.0\Grpc.Core.Api.dll
    Probed package dir and matched 'C:\Users\brettsam\.nuget\packages\grpc.core.api\2.38.1\lib\netstandard2.0\Grpc.Core.Api.dll'

in Preview 5:

Processing TPA for deps entry [Grpc.Core.Api, 2.38.1, lib/netstandard2.0/Grpc.Core.Api.dll]
  Considering entry [Grpc.Core.Api/2.38.1/lib/netstandard2.0/Grpc.Core.Api.dll], probe dir [], probe fx level:0, entry fx level:0
    Local path query C:\git\dotnet_6\azure-functions-host\test\WebJobs.Script.Tests\bin\Debug\net6.0\Grpc.Core.Api.dll (skipped file existence check)
    Probed deps dir and matched 'C:\git\dotnet_6\azure-functions-host\test\WebJobs.Script.Tests\bin\Debug\net6.0\Grpc.Core.Api.dll'

I noticed the skipped file existence check log was added here: #50671, so I'm curious if this is by design or if there's something that we need to tweak to get this running again.

Pinging @mateoatr as the PR author.

Tagging subscribers to this area: @vitek-karas, @agocke, @VSadov
See info in area-owners.md if you want to be subscribed.

Issue Details

---

I'm on the Azure Functions team and as I moved us forward to preview 5, we started getting this in our CI build while running tests:

System.IO.FileNotFoundException: 'Could not load file or assembly 'Grpc.Core.Api, Version=2.0.0.0, Culture=neutral, PublicKeyToken=d754f35622e28bad'. The system cannot find the file specified.'

I'm able to repro this locally. When I switch back to preview 4, it goes away.

I enabled CORHOST_TRACE to see what looked different and here's what I see when I look for Grpc.Core.Api:

in Preview 4

Processing TPA for deps entry [Grpc.Core.Api, 2.38.1, lib/netstandard2.0/Grpc.Core.Api.dll]
  Considering entry [Grpc.Core.Api/2.38.1/lib/netstandard2.0/Grpc.Core.Api.dll], probe dir [], probe fx level:0, entry fx level:0
    Local path query did not exist C:\git\dotnet_6\azure-functions-host\test\WebJobs.Script.Tests\bin\Debug\net6.0\Grpc.Core.Api.dll
    Skipping... not found in deps dir 'C:\git\dotnet_6\azure-functions-host\test\WebJobs.Script.Tests\bin\Debug\net6.0\'
    Skipping... not found in probe dir ''
  Considering entry [Grpc.Core.Api/2.38.1/lib/netstandard2.0/Grpc.Core.Api.dll], probe dir [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App\6.0.0-preview.4.21253.5], probe fx level:1, entry fx level:0
    Skipping... not found in deps json.
    Skipping... not found in probe dir 'C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App\6.0.0-preview.4.21253.5'
  Considering entry [Grpc.Core.Api/2.38.1/lib/netstandard2.0/Grpc.Core.Api.dll], probe dir [C:\Program Files\dotnet\shared\Microsoft.NETCore.App\6.0.0-preview.4.21253.7], probe fx level:2, entry fx level:0
    Skipping... not found in deps json.
    Skipping... not found in probe dir 'C:\Program Files\dotnet\shared\Microsoft.NETCore.App\6.0.0-preview.4.21253.7'
  Considering entry [Grpc.Core.Api/2.38.1/lib/netstandard2.0/Grpc.Core.Api.dll], probe dir [C:\Users\brettsam\.nuget\packages], probe fx level:-1, entry fx level:0
    Relative path query exists C:\Users\brettsam\.nuget\packages\grpc.core.api\2.38.1\lib\netstandard2.0\Grpc.Core.Api.dll
    Probed package dir and matched 'C:\Users\brettsam\.nuget\packages\grpc.core.api\2.38.1\lib\netstandard2.0\Grpc.Core.Api.dll'

in Preview 5:

Processing TPA for deps entry [Grpc.Core.Api, 2.38.1, lib/netstandard2.0/Grpc.Core.Api.dll]
  Considering entry [Grpc.Core.Api/2.38.1/lib/netstandard2.0/Grpc.Core.Api.dll], probe dir [], probe fx level:0, entry fx level:0
    Local path query C:\git\dotnet_6\azure-functions-host\test\WebJobs.Script.Tests\bin\Debug\net6.0\Grpc.Core.Api.dll (skipped file existence check)
    Probed deps dir and matched 'C:\git\dotnet_6\azure-functions-host\test\WebJobs.Script.Tests\bin\Debug\net6.0\Grpc.Core.Api.dll'

I noticed the skipped file existence check log was added here: #50671, so I'm curious if this is by design or if there's something that we need to tweak to get this running again.

Pinging @mateoatr as the PR author.

Author:	brettsam
Assignees:	-
Labels:	area-Host, untriaged
Milestone:	-

[brettsam]

After talking with @mateoatr -- the underlying issue here was that our runtimeconfig.dev.json was not generated (based on this -- dotnet/sdk#17014).

Adding <GenerateRuntimeConfigDevFile>true</GenerateRuntimeConfigDevFile> got us building again.

However, there may be some issue with our build as this should not be required anymore. I will continue investigation on the MSBuild side.

[vitek-karas]

It seems this is resolved - at least from the host perspective. Please create a new issue if there is anything else we can help with.