The err parameter for the tracing::instrument macro logs at error
level unconditionally when the Result-returning function returns, err,
Err. This was once useful for debugging, but nowadays adds noise: it
is often hard to tell where the log line comes from, it's not always an
error (ie. it might be handled), or multiple log lines are emitted for
the same error condition.
The
errparameter for thetracing::instrumentmacro logs at error level unconditionally when theResult-returning function returns, err,Err. This was once useful for debugging, but nowadays adds noise: it is often hard to tell where the log line comes from, it's not always an error (ie. it might be handled), or multiple log lines are emitted for the same error condition.Thus, remove it everywhere.