[kinyoklion]

Summary

With ChangeDetection(Watching), a file override source whose file watcher cannot be created, for example because the limit on inotify instances is reached, logged "Unable to watch override files" and ran with no change detection at all. A later edit, creation, or deletion of an override file never took effect, which the OVERRIDE specification's Requirement 1.3.7 does not allow ("detecting changes by watching the files or by polling them, according to platform support").

The source now falls back to polling in that case. It logs at Error level "Unable to watch override files; polling them instead every {interval}: {reason}" and polls at the configured interval raised to MinimumPollInterval, because watching mode otherwise ignores the minimum. Polling mode and a watcher that starts normally are unchanged; the watcher's own retry for a directory it cannot watch yet is unchanged.

The same gap was found by Bugbot on the Java implementation (launchdarkly/java-core#224) and is fixed there the same way.

Testing

TestFileSourceWatchingModeFallsBackToPollingWhenTheWatcherCannotBeCreated replaces the watch setup with one that fails, then checks that an edit is applied by polling and that the error is logged. With the poller creation removed, the test fails. go test -race ./... passes (31 packages) and make lint reports no issues.

_{Opened from termag}

SDK-3419

---

Note

Overview
Watching mode for file override sources no longer leaves change detection disabled when the OS cannot create a file watcher (for example inotify limits). The source falls back to polling at the configured PollInterval, clamped to MinimumPollInterval, and logs an error that includes the poll interval and failure reason.

Production wiring is unchanged via an injectable watchFiles hook (default ldfilewatch.WatchOptionalFiles) so tests can simulate watcher creation failure. Polling mode and successful watchers are unaffected.

A new test verifies that edits are picked up via polling and that the fallback error message is logged.

^{Reviewed by Cursor Bugbot for commit ea03508. Bugbot is set up for automated code reviews on this repo. Configure here.}

[kinyoklion]

bugbot review

[cursor]

✅ Bugbot reviewed your changes and found no new issues!

Comment @cursor review or bugbot run to trigger another review on this PR

^{Reviewed by Cursor Bugbot for commit ea03508. Configure here.}