描述

Ubuntu 22.04运行以下命令安装dotnet6 sdk后dotnet命令找不到sdk，安装命令如下：

apt update
apt install dotnet6

报错显示如下：

$ dotnet --version
The command could not be loaded, possibly because:
  * You intended to execute a .NET application:
      The application '--version' does not exist.
  * You intended to execute a .NET SDK command:
      No .NET SDKs were found.

Download a .NET SDK:
https://aka.ms/dotnet-download

Learn about SDK resolution:
https://aka.ms/dotnet/sdk-not-found

进一步查看：

$ dotnet --info

global.json file:
  Not found

Host:
  Version:      6.0.8
  Architecture: x64
  Commit:       55fb7ef977

.NET SDKs installed:
  No SDKs were found.

.NET runtimes installed:
  Microsoft.AspNetCore.App 6.0.8 [/usr/lib/dotnet/dotnet6-6.0.108/shared/Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 6.0.8 [/usr/lib/dotnet/dotnet6-6.0.108/shared/Microsoft.NETCore.App]

Download .NET:
  https://aka.ms/dotnet-download

Learn about .NET Runtimes and SDKs:
  https://aka.ms/dotnet/runtimes-sdk-info

很明显，这里sdk没有被识别，但肯定已经安装了（apt命令能查到）

解决方案

大概率是因为版本不识别，尝试下面命令即可：

$ sudo apt install aspnetcore-runtime-6.0=6.0.8-1 dotnet-apphost-pack-6.0=6.0.8-1 dotnet-host=6.0.8-1 dotnet-hostfxr-6.0=6.0.8-1 dotnet-runtime-6.0=6.0.8-1 dotnet-sdk-6.0=6.0.400-1 dotnet-targeting-pack-6.0=6.0.8-1

参考资料

https://github.com/dotnet/sdk/issues/27082
https://devblogs.microsoft.com/dotnet/dotnet-6-is-now-in-ubuntu-2204/