Logging
Eventuous uses the ASP.NET Core logging with ILoggerFactory and ILogger<T>, so you can use the standard logging facilities to log diagnostics. For internal logging, Eventuous uses multiple event sources, which you can collect and analyse with tools like dotnet-trace.
It's also possible to expose internal Eventuous logs using the UseEventuousLogs extension for IHost, which is available as part of Eventuous.Extensions.DependencyInjection package.