I had the same problem. You need to have an ASP.NET runtime.
It’s a bit confusing and easily overlooked, but it says you need an Microsoft.
AspNetCore
.App
runtime, and your dotnet --list-runtimes
only lists Microsoft.
NETCore
.App
s.
The ArchWiki mentions:
This is caused because the runtime is shipped as a separate package in Arch. You just need to make sure you have the
aspnet-runtime
package installed as well.
To install the .NET 5 runtime:
sudo pacman -Sy aspnet-runtime
or if you need the 3.1 version:
sudo pacman -Sy aspnet-runtime-3.1
Now there’s an ASP runtime available:
$ dotnet --list-runtimes
Microsoft.AspNetCore.App 5.0.4 [/usr/share/dotnet/shared/Microsoft.AspNetCore.App] # <<<
Microsoft.NETCore.App 5.0.4 [/usr/share/dotnet/shared/Microsoft.NETCore.App]