Section 52.4 What a Consumer Learns

PreTeXt is normally driven as a library by a separate command-line program, which is in turn driven by tools such as an online textbook platform. Such a tool sees only what reaches it: the severity of each logged message, and whether the build raised PreTeXtFatal. From these the command-line layer can report the two outcomes an author cares about—the build finished but had non-fatal errors, or the build did not happen at all—without inspecting the text of any message. For that to work, this library’s obligation is simply to log every message at an honest severity, to route all messages through the shared logger, and to reserve fatal for a genuine halt.