SWI-Prolog -- debug_message

Documentation
- Reference manual
  - The SWI-Prolog library
    - library(debug): Print debug messages and test assertions
- Packages

Availability::- use_module(library(debug)).(can be autoloaded)

[det]debug_message_context(+What)

Specify additional context for debug messages. What is one of +Context or -Context, and Context is one of thread, time or time(Format), where Format is a format specification for format_time/3 (default is %T.%3f). Initially, debug/3 shows only thread information.