I'm getting an error within the gRPC code:

Grpc.AspNetCore.Server.ServerCallHandler: Error: Error when executing service method 'Run'.

Pulumi.LogException: Error occurred during logging
 ---> Grpc.Core.RpcException: Status(StatusCode="Unavailable", Detail="failed to connect to all addresses", DebugException="Grpc.Core.Internal.CoreErrorDetailException: {"created":"@1615315279.587000000","description":"Failed to pick subchannel","file":"..\..\..\src\core\ext\filters\client_channel\<http://client_channel.cc|client_channel.cc>","file_line":4143,"referenced_errors":[{"created":"@1615315279.467000000","description":"failed to connect to all addresses","file":"..\..\..\src\core\ext\filters\client_channel\lb_policy\pick_first\<http://pick_first.cc|pick_first.cc>","file_line":398,"grpc_status":14}]}")
   at Pulumi.GrpcEngine.LogAsync(LogRequest request)
   at Pulumi.Deployment.Logger.LogAsync(LogSeverity severity, String message, Resource resource, Nullable`1 streamId, Nullable`1 ephemeral)

Any ideas? Additional output:

Microsoft.Hosting.Lifetime: Information: Now listening on: <http://0.0.0.0:63544>
Microsoft.Hosting.Lifetime: Information: Application started. Press Ctrl+C to shut down.
Microsoft.Hosting.Lifetime: Information: Hosting environment: Production
Microsoft.Hosting.Lifetime: Information: Content root path: C:\repos\Atlas.Infrastructure.Templates\tests\Atlas.Infrastructure.Templates.Tests.Integration\bin\Debug\netcoreapp3.1
'testhost.exe' (CoreCLR: clrhost): Loaded 'C:\Program Files\dotnet\shared\<http://Microsoft.NETCore.App|Microsoft.NETCore.App>\3.1.11\System.Runtime.CompilerServices.Unsafe.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
'testhost.exe' (CoreCLR: clrhost): Loaded 'C:\Program Files\dotnet\shared\<http://Microsoft.NETCore.App|Microsoft.NETCore.App>\3.1.11\System.Numerics.Vectors.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
Microsoft.AspNetCore.Hosting.Diagnostics: Information: Request starting HTTP/2 POST <http://127.0.0.1:63544/pulumirpc.LanguageRuntime/GetRequiredPlugins> application/grpc 
'testhost.exe' (CoreCLR: clrhost): Loaded 'C:\Program Files\dotnet\shared\<http://Microsoft.AspNetCore.App|Microsoft.AspNetCore.App>\3.1.11\Microsoft.AspNetCore.Metadata.dll'. Skipped loading symbols. Module is optimized and the debugger option 'Just My Code' is enabled.
Microsoft.AspNetCore.Routing.EndpointMiddleware: Information: Executing endpoint 'gRPC - /pulumirpc.LanguageRuntime/GetRequiredPlugins'
Microsoft.AspNetCore.Routing.EndpointMiddleware: Information: Executed endpoint 'gRPC - /pulumirpc.LanguageRuntime/GetRequiredPlugins'
Microsoft.AspNetCore.Hosting.Diagnostics: Information: Request starting HTTP/2 POST <http://127.0.0.1:63544/pulumirpc.LanguageRuntime/Run> application/grpc 
Microsoft.AspNetCore.Hosting.Diagnostics: Information: Request finished in 88.9516ms 200 application/grpc
Microsoft.AspNetCore.Routing.EndpointMiddleware: Information: Executing endpoint 'gRPC - /pulumirpc.LanguageRuntime/Run'
The thread 0x767c has exited with code 0 (0x0).
Microsoft.Hosting.Lifetime: Information: Application is shutting down...

Might still be worth opening an issue if the error output is getting swallowed or hidden in some way.

Actually I figured it out for one stack, but am still having issues with another. https://github.com/pulumi/pulumi/issues/6494