An exclude pattern that did not compile was skipped with a warning during the backup, which then stored what the user meant to leave out. Config.Validate now refuses it, naming the setting and quoting the pattern, for example exclude[2]: "build[" is not a valid exclude pattern: ...
The compile step moves to a new package, internal/exclude, as exclude.Compile; Validate and the scanner both call it. The scanner's skip-and-warn path is gone; a pattern that does not compile there now fails the scanner.
Model: opus-5-5