puppetlabs/puppet · error · RuntimeError

Diff is not supported on this platform

Error message

Diff is not supported on this platform

What it means

Dipper#diff raises RuntimeError when the `diff` Puppet setting is an empty string, which means no diff binary is configured for this platform. Since diffing is the entire purpose of the call, `puppet filebucket diff` and any Ruby caller abort instead of producing an empty comparison.

Source

Thrown at lib/puppet/file_bucket/dipper.rb:65

      file_bucket_path = "#{@rest_path}#{file_bucket_file.checksum_type}/#{file_bucket_file.checksum_data}/#{files_original_path}"

      # Make a HEAD request for the file so that we don't waste time
      # uploading it if it already exists in the bucket.
      unless Puppet::FileBucket::File.indirection.head(file_bucket_path, :bucket_path => file_bucket_file.bucket_path)
        Puppet::FileBucket::File.indirection.save(file_bucket_file, dest_path)
      end

      file_bucket_file.checksum_data
    rescue => detail
      message = _("Could not back up %{file}: %{detail}") % { file: file, detail: detail }
      Puppet.log_exception(detail, message)
      raise Puppet::Error, message, detail.backtrace
    end
  end

  # Diffs two filebucket files identified by their sums
  def diff(checksum_a, checksum_b, file_a, file_b)
    raise RuntimeError, _("Diff is not supported on this platform") if Puppet[:diff] == ""

    if checksum_a
      source_path = "#{@rest_path}#{@checksum_type}/#{checksum_a}"
      if checksum_b
        file_diff = Puppet::FileBucket::File.indirection.find(
          source_path,
          :bucket_path => @local_path,
          :diff_with => checksum_b
        )
      elsif file_b
        tmp_file = ::Tempfile.new('diff')
        begin
          restore(tmp_file.path, checksum_a)
          file_diff = Puppet::Util::Diff.diff(tmp_file.path, file_b)
        ensure
          tmp_file.close
          tmp_file.unlink
        end

View on GitHub (pinned to e227c27540)

Solutions

1. Set a real diff binary in the [main] section of puppet.conf: `diff = /usr/bin/diff`
2. On Windows, install a diff tool (Git for Windows ships one) and point the setting at diff.exe
3. If diff is intentionally disabled, fetch both checksums with `puppet filebucket get` and compare them externally

Example fix

# before
[main]
diff = ""
# after
[main]
diff = /usr/bin/diff

if Puppet[:diff].to_s.strip.empty?
  Puppet.info 'diff disabled (Puppet[:diff] is empty); skipping bucket diff'
  return
end
dipper.diff(a, b)

begin
  dipper.diff(sum_a, sum_b)
rescue RuntimeError => e
  raise unless e.message == 'Diff is not supported on this platform'
  Puppet.info 'diff binary not configured; falling back to checksum comparison'
end

When it happens

Trigger: Puppet[:diff] == '' — set explicitly in puppet.conf (`diff = ""`), defaulted empty on platforms where Puppet cannot locate a diff tool (typically Windows), then invoking `puppet filebucket diff ...` or Dipper#diff.

Common situations: Windows nodes without a diff utility installed; hardened configurations that blank the diff setting to suppress content in logs; later needing diff output on the same node.

Related errors

• Cannot determine basic system flavour
• Please provide a file or checksum to diff with
• Failed to diff files
• RegisterEventSourceW failed to open Windows eventlog
• ReportEventW failed to report event to Windows eventlog

AI-assisted analysis of puppetlabs/puppet@e227c27540 (2026-08-21). Data as JSON: /api/errors/3e9c1db79451a255. Report an issue: GitHub.