Logging

Logs go to stderr, formatted for a terminal when stderr is one and as JSON otherwise; --log overrides that choice. Colour follows the same rule, and --color overrides it. -v adds per-connection events, -vv adds trace output, and -q restricts output to warnings and errors. The HAWSE_LOG environment variable takes a tracing filter directive and overrides all of them.

On a terminal the client prints a header when it connects and a row for each service in place of its log lines, and the server a header when it starts and a row for each client and service, with warnings and errors logged beside them. --log pretty, -v, -q and HAWSE_LOG each bring the log lines back.