Structured Logging

Bind *process-logger* to a cl-log-kit logger (see cl-log-kit's log-kit:make-logger) to observe process launch outcomes, timeout/ cancellation signal escalation, and pipeline stage failures as structured log records:

(let ((process-kit:*process-logger*
        (log-kit:make-logger :name "my-app" :handler (make-instance 'log-kit:json-handler))))
  (process-kit:run "sleep" (list "10") :timeout 1))

*process-logger* defaults to nil, which keeps the library silent exactly as before observability was added.

Binding scope and the cancellation watcher thread

Most lifecycle records — launch outcomes, timeout escalation, pipeline stage failure — are emitted on the calling thread, so a thread-local let binding of *process-logger* observes them.

The cancellation escalation record, however, is emitted from an internal watcher thread, and an SBCL thread reads a special variable's global value rather than the spawning thread's dynamic binding. To observe every record, including cancellation escalation, install the logger globally:

(setf process-kit:*process-logger* logger)

rather than binding it dynamically around a single call.