What causes "no files matching pattern %q" in apache/beam?

Fix the glob pattern — test it with filesystem.Match or gsutil/ls locally against the same paths

no files matching pattern

Error message

no files matching pattern %q

What it means

fileio.MatchAll's ProcessElement expands the glob against the filesystem and, when zero files match and EmptyTreatment does not allow an empty match, fails with this error. It exists to surface likely-mistyped paths/permissions instead of silently producing an empty pipeline.

Solutions

Fix the glob pattern — test it with filesystem.Match or gsutil/ls locally against the same paths
Set EmptyTreatment: fileio.EmptyTreatmentAllow in the MatchAll options when an empty match is legitimate
Verify the upstream job that produces the files completed and wrote to the expected location
Check filesystem/permissions: the worker must be able to list the containing directory

Example fix

// before
matches := fileio.MatchAll(s, fileio.MatchAllEmptyTreatment(0), glob)
// after: allow legitimately empty matches
matches := fileio.MatchAll(s, fileio.MatchAllEmptyTreatment(fileio.EmptyTreatmentAllow), glob)

Defensive patterns

Strategy: fallback

Validate before calling

matched, _ := fs.List(context.Background(), pattern)
if len(matched) == 0 {
	// verify upstream producer ran, or switch EmptyTreatment to Allow
}

Try / catch

defer func() {
	if r := recover(); r != nil {
		log.Printf("glob %q matched nothing; check upstream producer or EmptyTreatmentAllow", glob)
	}
}()

Prevention

Test globs locally with filesystem.Match against the real store before running the pipeline
Use EmptyTreatmentAllow when an empty input is a valid state (e.g. hourly partitions)
Verify the upstream job finished and paths exist from the worker's network/permissions

When it happens

Trigger: len(files) == 0 after Match(ctx, fs, glob) and allowEmptyMatch(glob, fn.EmptyTreatment) is false (match.go:152) — i.e. EmptyTreatment is EmptyTreatmentDisallow (default) or EmptyTreatmentIfNonEmptyMatch semantics.

Common situations: Typo in the glob or path; input directory empty because the upstream producer hasn't run; files stored on a filesystem view the worker can't see (wrong container/FS registration); date-partitioned path for the wrong day.

Understand the failure class

Background: "File not found" and ENOENT errors: why libraries can't find a file that should exist — this error's family across 50 libraries.

Related errors

AI-assisted analysis of apache/beam@12126d8942 (2026-09-13). Data as JSON: /api/errors/1dac8269d1e630bf. Report an issue: GitHub.

Appendix: source

Thrown at sdks/go/pkg/beam/io/fileio/match.go:152

) error {
	if strings.TrimSpace(glob) == "" {
		return nil
	}

	fs, err := filesystem.New(ctx, glob)
	if err != nil {
		return err
	}
	defer fs.Close()

	files, err := fs.List(ctx, glob)
	if err != nil {
		return err
	}

	if len(files) == 0 {
		if !allowEmptyMatch(glob, fn.EmptyTreatment) {
			return fmt.Errorf("no files matching pattern %q", glob)
		}
		return nil
	}

	metadata, err := metadataFromFiles(ctx, fs, files)
	if err != nil {
		return err
	}

	for _, md := range metadata {
		emit(md)
	}

	return nil
}

func allowEmptyMatch(glob string, treatment emptyTreatment) bool {
	switch treatment {

View on GitHub (pinned to 12126d8942)