Quick-and-dirty ANSI highlight of standard Ruby backtraces

hl_backtrace.rb

puts caller.map{|l|
  l.sub(
    %r{/([^:/]+):(\d+):in `([^']*)'},
    "/\e[33m\\1\e[0m:\e[34m\\2\e[0m:in `\e[1;35m\\1\e[0m'"
  )
}

hl_backtrace_better_with_outline.rb

# Returns a String of the message and backtrace with ANSI highlighting and an
# outline in Unicode box drawing characters.  The +backtrace+ can also be an
# Exception.
#
# Example:
#     puts hl_bt(caller(1), 'Here I am')
def hl_bt(backtrace, msg=nil)
  require 'io/console'

  if backtrace.is_a?(Exception)
    msg = [msg, backtrace.message].compact.join(': ')
    backtrace = backtrace.backtrace
    color = "\e[31m"
  else
    color = "\e[34m"
  end

  width = IO.console.winsize[1] rescue 80
  divider = "#{"\u2500" * (width - 3)}\u257c\e[0m"
  leader = "#{color}\u2502\e[0m"

  str = "#{color}\u256d#{divider}\n"

  str << "#{leader}\e[1m#{msg}\e[0m\n" if msg

  str << backtrace.reject{|l|
    # Skip gems we don't care about
    l =~ %r{(gems/(act|factory|rack|rail|state|warden|capybara|rspec|unicorn|newrelic|quiet_assets|meta_request|bullet)|webrick)}
  }.map{|l|
    # Skip leading paths
    l = l[/(rubies|gems).*/] || l
    l = l[%r{/gems.*}] || l

    # Highlight the line
    "#{leader}  \e[36m" + l.sub(
      %r{/([^:/]+):(\d+):in `([^']*)'},
      "/\e[1;33m\\1\e[0m:\e[34m\\2\e[0m:in `\e[1;35m\\3\e[0m'\n"
    )
  }.join

  str << "#{color}\u2514#{divider}\n"

  str
end

From https://github.com/deseretbook/spree_address_management/blob/7df3dffffc878c7370f04c9dfc0c589c1c063808/app/helpers/spree/addresses_helper.rb#L80-L123