sj26/mailcatcher · info

Please submit this as an issue at https://github.com/sj2

Error message

    Please submit this as an issue at https://github.com/sj26/mailcatcher/issues

What it means

The closing line of log_exception (lib/mail_catcher.rb:64): after printing context, exception, and backtrace, MailCatcher asks you to submit the report as a GitHub issue. It means the failure was unexpected enough that the library has no built-in remedy — it only guarantees the process keeps running (the callers rescue-and-continue).

Source

Thrown at lib/mail_catcher.rb:64

  end

  def browse url
    if windows?
      system "start", "/b", url
    elsif which? "open"
      system "open", url
    end
  end

  def log_exception(message, context, exception)
    gems_paths = (Gem.path | [Gem.default_dir]).map { |path| Regexp.escape(path) }
    gems_regexp = %r{(?:#{gems_paths.join("|")})/gems/([^/]+)-([\w.]+)/(.*)}
    gems_replace = '\1 (\2) \3'

    puts "*** #{message}: #{context.inspect}"
    puts "    Exception: #{exception}"
    puts "    Backtrace:", *exception.backtrace.map { |line| "       #{line.sub(gems_regexp, gems_replace)}" }
    puts "    Please submit this as an issue at https://github.com/sj26/mailcatcher/issues"
  end

  @@defaults = {
    :smtp_ip => "127.0.0.1",
    :smtp_port => "1025",
    :http_ip => "127.0.0.1",
    :http_port => "1080",
    :http_path => "/",
    :messages_limit => nil,
    :verbose => false,
    :daemon => !windows?,
    :browse => false,
    :quit => true,
  }

  def options
    @@options
  end

View on GitHub (pinned to 18a9cb7a79)

Solutions

1. Judge reportability by the Exception line: connection/disconnect classes (EPIPE, IOError) are noise; SQLite3 or parse errors that reproduce on the latest mailcatcher release are worth filing.
2. Before filing, reproduce on the newest version (`gem update mailcatcher`) and with `--foreground --verbose`.
3. File at https://github.com/sj26/mailcatcher/issues including all four printed lines (context, exception, backtrace) plus the sender/recipient shape and Ruby/gem versions.
4. If it stems from an incompatible sqlite3/mail version, fix locally by pinning rather than reporting.

# Wrap your own embedding path; only surface the report-worthy subset to GitHub
begin
  MailCatcher::Mail.add_message(msg)
rescue => e
  reportable = !(e.is_a?(IOError) || e.is_a?(Errno::EPIPE))
  warn "submit-as-issue candidate: #{e.class}: #{e.message}" if reportable
end

When it happens

Trigger: Printed after every exception funneled through log_exception: message-persistence failures in MailCatcher::Smtp#receive_message and websocket send failures in the /messages WS handler. You see it whenever either rescue fires, even for benign causes like a disconnected browser.

Common situations: Deciding whether an intermittent `Error sending message through websocket` report is worth reporting (usually not — it's a closed client); preparing a bug report for a repeatable `Error receiving message` crash; pasting the block into a GitHub issue after a gem upgrade broke mail storage.

Related errors

• *** #{message}: #{context.inspect}
• Exception: #{exception}
• Backtrace:

AI-assisted analysis of sj26/mailcatcher@18a9cb7a79 (2026-08-21). Data as JSON: /api/errors/a50642bffbe474ee. Report an issue: GitHub.