Rails formatted backtrace on logger (tested in Rails 3.0.10)

backtrace_silencers.rb

Rails.backtrace_cleaner.remove_silencers!

Rails.backtrace_cleaner.add_silencer { |line| line =~ /spec/ }

module ActiveSupport
  class BacktraceCleaner
    def clean_with_format(backtrace, kind = :silent)
      filtered = clean_without_format(backtrace, kind)

      splits = filtered.map do |line|
        gem, version, line, method = line.split
        gem, version, line, method = '', '', gem, version unless line
        [ gem, version, [ line, method ].join(' ') ]
      end

      lengths = splits.map do |gem, version, place|
        [ gem.length, version.length, 0 ]
      end.transpose.map(&:max)

      splits.map do |items|
        items.zip(lengths).map do |item, length|
          item.ljust(length)
        end.join(' ')
      end
    end
    alias_method_chain :clean, :format
  end
end

verbose_fatal_error.rb

module ActiveSupport
  class BufferedLogger
    def error_with_backtrace(e)
      if e.is_a?(Exception)
        [ e.to_s, Rails.backtrace_cleaner.clean(e.backtrace) ].join("\n")
      else
        e
      end
    end

    def fatal_with_backtrace(message = nil, progname = nil, &block)
      fatal_without_backtrace(error_with_backtrace(message), progname, &block)
    end
    alias_method_chain :fatal, :backtrace
  end
end