我正在尝试dotnet-ef通过 dotnet-cli安装该工具。
我输入的命令： dotnet tool install --global dotnet-ef
我给了我以下错误：
The tool package could not be restored.
Tool 'dotnet-ef' failed to install. This failure may have been caused by:
* You are attempting to install a preview release and did not use the --version option to specify the version.
* A package by this name was found, but it was not a .NET Core tool.
* The required NuGet feed cannot be accessed, perhaps because of an Internet connection …