.NET 5 RC 2

[rbhanda]

Release Notes

Please report any issues you find with .NET 5, either responding to this issue, creating a new issue or creating a new issue in one of the following repos:

• dotnet/aspnetcore - for ASP.NET Core questions
• dotnet/efcore - for Entity Framework Core questions
• dotnet/sdk - for CLI tools and questions
• dotnet/runtime - for runtime, API, or installer issues and questions
• dotnet/winforms - for WinForms issues
• dotnet/wpf - for WPF issues
• nuget/home - for NuGet questions and issues

Known Issues

If there are any issues with the October 2020 release we will track them here and check issues off as they're resolved. See the linked issues for details on progress and resolution details.

• [x] 5.0 release.json is malformed https://github.com/dotnet/core/issues/5342
• [x] 5.0 Link for 5.0 RC2 release notes in 5.0 release.json is incorrect. This was resolved by https://github.com/dotnet/core/pull/5349
• [x] Microsoft.DotNet.Mage is not available on Nuget.org - Resolved by https://github.com/dotnet/deployment-tools/pull/42.
• [x] Unable to install 5.0 RC2 on Ubuntu 20.10 https://github.com/dotnet/core/issues/5352

[reinux]

This problem persists on my machine with RC2 (RC1 uninstalled).

Even just using .fsx, with preview language features enabled, I get a slew of errors:

Error FS3217 error NU1102: Unable to find package FSharp.Core with version (>= 5.0.0) F# Miscellaneous Files
Error FS3217 error NU1102: - Found 35 version(s) in nuget.org [ Nearest version: 5.0.0-beta.20417.1 ] F# Miscellaneous Files Error FS3217 error NU1102: - Found 0 version(s) in Microsoft Visual Studio Offline Packages F# Miscellaneous Files

[mairaw]

Tagging @cartermp and @KathleenDollard

[TropicalThunder]

Severity Code Description Project File Line Suppression State Error NETSDK1130 Referencing a Windows Metadata component directly when targeting .NETCoreApp,Version=v5.0 is not supported. Use the C#/WinRT projection tool (https://aka.ms/cswinrt) or a provided projection for this target. Project.SomeName C:\Program Files\dotnet\sdk\5.0.100-rc.2.20479.15\Sdks\Microsoft.NET.Sdk\targets\Microsoft.NET.Sdk.targets 934

This is the new norm after I upgraded my project to RC2 - i cannot tell why it fails or what I'm supposed to do.

[ZacharyPatten]

:page_facing_up: NO LONGER AN ISSUE (Click To Expand)

_Sorry if this should be posted elsewhere..._ I've been seeing an issue in both Release Candidate 1 ~~and 2 **_(so it is not specific to rc2)_**~~ with **Blazor Webassembly Projects (targeting .NET 5)**. It appears like the `dotnet` executable is hanging after I stop debugging. So I can debug once, but successive times I get the following error: ``` The application is in break mode ``` 

:page_facing_up: Here is the content from the Copy Details (Click To Expand)

``` System.ArgumentNullException HResult=0x80004003 Message=Value cannot be null. (Parameter 'input') Source=System.Text.RegularExpressions StackTrace: at System.Text.RegularExpressions.ThrowHelper.ThrowArgumentNullException(ExceptionArgument arg) at System.Text.RegularExpressions.Regex.IsMatch(String input) at Microsoft.AspNetCore.Builder.DebugProxyLauncher.<>c__DisplayClass10_0.g__OnOutputDataReceived|0(Object sender, DataReceivedEventArgs eventArgs) at System.Diagnostics.Process.OutputReadNotifyUser(String data) at System.Diagnostics.AsyncStreamReader.FlushMessageQueue(Boolean rethrowInNewThread) at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() at System.Diagnostics.AsyncStreamReader.<>c.b__18_0(Object edi) at System.Threading.QueueUserWorkItemCallback.<>c.<.cctor>b__6_0(QueueUserWorkItemCallback quwi) at System.Threading.ExecutionContext.RunForThreadPoolUnsafe[TState](ExecutionContext executionContext, Action`1 callback, TState& state) at System.Threading.QueueUserWorkItemCallback.Execute() at System.Threading.ThreadPoolWorkQueue.Dispatch() at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback() This exception was originally thrown at this call stack: [External Code] ```

usually accompanied with the following pop-up  However, if (after a debugging session) I kill the `dotnet` process then it works just fine

:page_facing_up: Screenshot of killing dotnet process (Click To Expand)


It is pretty annoying to have to kill the process after every debugging attempt. Not sure if this is an issue unique to my machine or not. There are several errors in my event viewer. Here are several of those errors if it helps:

:page_facing_up: Event Viewer Entries (Click To Expand)

``` Application: dotnet.exe CoreCLR Version: 5.0.20.45114 .NET Version: 5.0.0-rc.1.20451.14 Description: The process was terminated due to an unhandled exception. Exception Info: System.IO.IOException: Failed to bind to address http://127.0.0.1:9300: address already in use. ---> Microsoft.AspNetCore.Connections.AddressInUseException: Only one usage of each socket address (protocol/network address/port) is normally permitted. ---> System.Net.Sockets.SocketException (10048): Only one usage of each socket address (protocol/network address/port) is normally permitted. at System.Net.Sockets.Socket.UpdateStatusAfterSocketErrorAndThrowException(SocketError error, String callerName) at System.Net.Sockets.Socket.DoBind(EndPoint endPointSnapshot, SocketAddress socketAddress) at System.Net.Sockets.Socket.Bind(EndPoint localEP) at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketConnectionListener.g__BindSocket|13_0(<>c__DisplayClass13_0& ) --- End of inner exception stack trace --- at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketConnectionListener.g__BindSocket|13_0(<>c__DisplayClass13_0& ) at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketConnectionListener.Bind() at Microsoft.AspNetCore.Server.Kestrel.Transport.Sockets.SocketTransportFactory.BindAsync(EndPoint endpoint, CancellationToken cancellationToken) at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Infrastructure.TransportManager.BindAsync(EndPoint endPoint, ConnectionDelegate connectionDelegate, EndpointConfig endpointConfig) at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServerImpl.<>c__DisplayClass29_0`1.<g__OnBind|0>d.MoveNext() --- End of stack trace from previous location --- at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindEndpointAsync(ListenOptions endpoint, AddressBindContext context) --- End of inner exception stack trace --- at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindEndpointAsync(ListenOptions endpoint, AddressBindContext context) at Microsoft.AspNetCore.Server.Kestrel.Core.LocalhostListenOptions.BindAsync(AddressBindContext context) at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.AddressesStrategy.BindAsync(AddressBindContext context) at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.AddressBinder.BindAsync(IEnumerable`1 listenOptions, AddressBindContext context) at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServerImpl.BindAsync(CancellationToken cancellationToken) at Microsoft.AspNetCore.Server.Kestrel.Core.KestrelServerImpl.StartAsync[TContext](IHttpApplication`1 application, CancellationToken cancellationToken) at Microsoft.AspNetCore.Hosting.WebHost.StartAsync(CancellationToken cancellationToken) at Microsoft.AspNetCore.Hosting.WebHostExtensions.RunAsync(IWebHost host, CancellationToken token, String startupMessage) at Microsoft.AspNetCore.Hosting.WebHostExtensions.RunAsync(IWebHost host, CancellationToken token, String startupMessage) at Microsoft.AspNetCore.Hosting.WebHostExtensions.RunAsync(IWebHost host, CancellationToken token) at Microsoft.AspNetCore.Hosting.WebHostExtensions.Run(IWebHost host) at Microsoft.WebAssembly.Diagnostics.Program.Main(String[] args) ``` ``` Category: Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware EventId: 1 SpanId: dbd6de15996bac46 TraceId: 236e38791cc6f2459a58da0636ca0d0f ParentId: 0000000000000000 RequestId: 80000072-0004-dc00-b63f-84710c7967bb RequestPath: /_framework/debug/ws-proxy An unhandled exception has occurred while executing the request. Exception: System.InvalidOperationException: No output has been recevied from the application. at Microsoft.AspNetCore.Builder.DebugProxyLauncher.LaunchAndGetUrl(IServiceProvider serviceProvider, String devToolsHost) at Microsoft.AspNetCore.Builder.WebAssemblyNetDebugProxyAppBuilderExtensions.<>c.<b__0_1>d.MoveNext() --- End of stack trace from previous location --- at Microsoft.AspNetCore.Builder.Extensions.MapMiddleware.Invoke(HttpContext context) at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context) ``` ``` Faulting application name: dotnet.exe, version: 5.0.20.47505, time stamp: 0x5f6e72a6 Faulting module name: KERNELBASE.dll, version: 10.0.18362.1049, time stamp: 0x1b835a75 Exception code: 0xe0434352 Fault offset: 0x0000000000043b29 Faulting process id: 0x694 Faulting application start time: 0x01d6a2373411d10d Faulting application path: C:\Program Files\dotnet\dotnet.exe Faulting module path: C:\WINDOWS\System32\KERNELBASE.dll Report Id: 265b30e8-4a1b-4ecf-a280-388a378f5f28 Faulting package full name: Faulting package-relative application ID: ```

EDIT: false alarm. this issue went away in rc2 after updating nuget packages.

[cartermp]

@reinux I cannot reproduce what you described on my windows or macOS machine with the latest RC2. Can you file a bug here with a detailed repro? https://github.com/dotnet/fsharp

[reinux]

I'm becoming more convinced that this is more of a problem with the SDK installer. C# projects fail as well.

Steps:

• Uninstall all versions of .NET Core and VS
• Install SDK 5.0.100-rc.2 using the x64 MSI
• dotnet new console (C# project)
• dotnet run
• dotnet build

Output:

C:\Program Files\dotnet\sdk\5.0.100-rc.2.20479.15\Microsoft.Common.CurrentVersion.targets(1180,5): error MSB3644: The reference assemblies for .NETFramework,Version=v5.0 were not found. To resolve this, install the Developer Pack (SDK/Targeting Pack) for this framework version or retarget your application. You can download .NET Framework Developer Packs at https://aka.ms/msbuild/developerpacks [C:\Users\rei\source\repos\Test3\Test3.csproj]

Edit:

Tried installing Visual Studio RC2. dotnet --version now shows 5.0.100-rc.2.20479.15, but it still gives me the same error. A new project made in VS just uses .NET Core 3.1. Clicking "Install other frameworks..." just takes me to the SDK download page.

[reinux]

Repairing the .NET 5 RC2 SDK fails. Here's the log file. Microsoft_.NET_SDK5.0.100-rc.2.20479.15(x64)_20201017040650.log

[rbhanda]

@joeloff Can you help here with .NET 5 RC2 SDK installation failure?

[joeloff]

@reinux can you try deleting this file: C:\ProgramData\Package Cache{35392F9B-1C64-368F-BBE1-CDFD0B381B94}v5.0.0.0\AspNetCoreSharedFramework-x64.msi

Then run repair again

[svick]

@waldimen That's the error you get when you try to compile a .Net 5.0 project using an older SDK. Did you follow the guide and ran sudo snap alias dotnet-sdk.dotnet dotnet?

[waldimen]

@svick I resolved it, it was caused by variable MSBuildSDKsPath set to net 3.1

[tanekim88]

Debugging blazorwebassembly hosted + .net 5 RC2 using F5 causes chrome browser to be launched with about:blank address, and after a while the following error occurs.

[Trolldemorted]

@reinux can you try deleting this file: C:\ProgramData\Package Cache{35392F9B-1C64-368F-BBE1-CDFD0B381B94}v5.0.0.0\AspNetCoreSharedFramework-x64.msi

Then run repair again

I did that, but I am still unable to select .net5 in VS, and if I edit the .csproj VS refuses to build (MSB3644). Running dotnet build directly works like a charm, though. I am running VS 16.7.7, and the installer did not nag me about pending updates so far.

[mairaw]

@Trolldemorted .NET 5 RC 2 requires Visual Studio 2019 (v16.8, Preview 4)

https://dotnet.microsoft.com/download/dotnet/5.0

You can download the preview from https://visualstudio.microsoft.com/vs/preview/

[rbhanda]

Closing in favor of https://github.com/dotnet/core/issues/5545