Today, I try the dedicated Aspire Cli. The installation went smoothly with:

dotnet tool install -g Aspire.Cli --prerelease

For more information: https://learn.microsoft.com/en-us/dotnet/aspire/cli/install

Running Aspire project is easy as well as I can be at any parent directory/folder and simply run the following command and it will search for AppHost.csproj recursively.

aspire run

However, during my attempt, it throws the following error:

The Aspire.Hosting package version 9.0.0 is not supported. Please update to the latest version.

So, I ensure all packages in my projects are updated to the latest, but it didn't work. I found out later that the Sdk was not updated as I still found the following entry in my AppHost.csproj file even after all packages updated to version 9.5.2.

<Sdk Name="Aspire.AppHost.Sdk" Version="9.0.0" />

Following the instructions in: https://learn.microsoft.com/en-us/dotnet/aspire/get-started/upgrade-to-aspire-9?pivots=dotnet-cli, I updated the version manually to 9.5.2 so it becomes:

<Sdk Name="Aspire.AppHost.Sdk" Version="9.5.2" />

Rerun the aspire run command and voilà! Back and running.