owasp-amass/amass · error

failed to copy the file %s: %v

Error message

failed to copy the file %s: %v

What it means

After creating the destination file, CreateDefaultConfigFiles copies the embedded file contents with io.Copy. This error means the copy operation failed — either writing to the destination file or (less likely) reading the embedded source failed mid-stream.

Source

Thrown at internal/tools/file.go:57

			// If the file already exists, skip creating it
			continue
		}

		file, err := resources.GetResourceFile(filename)
		if err != nil {
			return fmt.Errorf("failed to obtain the embedded file %s: %v", filename, err)
		}
		defer func() { _ = file.Close() }()

		// Create the default config file in the specified directory
		outFile, err := os.Create(filepath)
		if err != nil {
			return fmt.Errorf("failed to create the output file %s: %v", filepath, err)
		}
		defer func() { _ = outFile.Close() }()

		if _, err := io.Copy(outFile, file); err != nil {
			return fmt.Errorf("failed to copy the file %s: %v", filepath, err)
		}
	}
	return nil
}

View on GitHub (pinned to 79299dce87)

Solutions

1. Check free disk space and any quota (df -h, du on the volume)
2. Re-run the tool; if a partially written config remains, delete it first (os.Stat with the exists check will skip a truncated file otherwise)
3. Avoid running multiple instances concurrently against the same output directory
4. Check dmesg/journal for filesystem I/O errors and move the output directory to healthy storage

Example fix

// before
if _, err := io.Copy(outFile, file); err != nil { return ... }
// after
if _, err := io.Copy(outFile, file); err != nil {
	outFile.Close()
	os.Remove(filepath) // drop partial file so next run recreates it
	return fmt.Errorf("failed to copy the file %s: %v", filepath, err)
}

st, err := os.Stat(dirpath)
if err != nil || !st.IsDir() { return fmt.Errorf("output dir unusable") }
if us := getDiskFree(dirpath); us < 10*1024*1024 { return fmt.Errorf("less than 10MB free") }

for attempt := 0; attempt < 2; attempt++ {
	err := tools.CreateDefaultConfigFiles(dirpath)
	if err == nil { break }
	if strings.Contains(err.Error(), "failed to copy the file") && attempt == 0 {
		os.RemoveAll(filepath.Join(dirpath)) // clear partial files
		_ = tools.CreateOutputDirectory(dirpath)
		continue
	}
	return err
}

When it happens

Trigger: Disk becomes full while writing, the destination file descriptor hits an I/O error (bad sector, quota exceeded, network mount dropout), or the file is truncated/removed concurrently.

Common situations: Small disk partitions or container quota limits exhausted during initialization; NFS/EBS volumes losing connectivity mid-copy; concurrent runs racing on the same output directory.

Understand the failure class

Background: "failed to write file", "Could not save figure", "Error saving remote file" — file write failed: causes and fixes across languages and libraries — this error's family across 38 libraries.

Related errors

• failed to obtain the path for the output directory
• failed to get executable path: %w
• mkdir failed for %s: %v
• failed to set permissions to 0755 for %s: %v
• failed to create the output file %s: %v

AI-assisted analysis of owasp-amass/amass@79299dce87 (2026-09-06). Data as JSON: /api/errors/a3be93332e586bc0. Report an issue: GitHub.