Rewrite Ruby's backtrace to cover your tracks

gistfile1.rb

this_file = Regexp.new(__FILE__)

# Capture every single time an exception is raised in this Ruby program.
# Use TracePoint for Ruby 2.0+, set_trace_func for Ruby 1.9-
trace = TracePoint.new(:raise) do |tp|

  exception = tp.raised_exception
  backtrace = exception.backtrace

  # if the source of the error is in this file
  if backtrace.any?{|b| b =~ this_file}
    # Remove all lines in the backtrace that match this filename
    # as well as lines with the word "require", which could help
    # point to this filename. The result is a backtrace which hides
    # the source of the error while still appearing like a credible
    # backtrace.
    filtered_backtrace = backtrace.select do |bt|
      bt !~ this_file && bt !~ /require/
    end
    # This is what is referred to as "lying":
    exception.set_backtrace(filtered_backtrace)
  end

end

trace.enable

raise "good luck finding me!"