https://github.com/asenchi/scrolls/pull/51#issuecomment-33124964

manufacture_backtraces.rb

def raise_error_with_at_least_n_backtrace_lines(n)
  raise 'Boom!' if caller.length >= n
  raise_error_with_at_least_n_backtrace_lines(n)
end

require 'pp'
def demo(n)
  puts "n = #{n}"
  puts "*" * 80
  begin
    raise_error_with_at_least_n_backtrace_lines n
  rescue StandardError => e
    pp e.backtrace
  end
end

demo(1)

demo(20)

results.txt

$ ruby manufacture_backtraces.rb

n = 1
********************************************************************************
["manufacture_backtraces.rb:2:in `raise_error_with_at_least_n_backtrace_lines'",
 "manufacture_backtraces.rb:11:in `demo'",
 "manufacture_backtraces.rb:17:in `<main>'"]
n = 20
********************************************************************************
["manufacture_backtraces.rb:2:in `raise_error_with_at_least_n_backtrace_lines'",
 "manufacture_backtraces.rb:3:in `raise_error_with_at_least_n_backtrace_lines'",
 "manufacture_backtraces.rb:3:in `raise_error_with_at_least_n_backtrace_lines'",
 "manufacture_backtraces.rb:3:in `raise_error_with_at_least_n_backtrace_lines'",
 "manufacture_backtraces.rb:3:in `raise_error_with_at_least_n_backtrace_lines'",
 "manufacture_backtraces.rb:3:in `raise_error_with_at_least_n_backtrace_lines'",
 "manufacture_backtraces.rb:3:in `raise_error_with_at_least_n_backtrace_lines'",
 "manufacture_backtraces.rb:3:in `raise_error_with_at_least_n_backtrace_lines'",
 "manufacture_backtraces.rb:3:in `raise_error_with_at_least_n_backtrace_lines'",
 "manufacture_backtraces.rb:3:in `raise_error_with_at_least_n_backtrace_lines'",
 "manufacture_backtraces.rb:3:in `raise_error_with_at_least_n_backtrace_lines'",
 "manufacture_backtraces.rb:3:in `raise_error_with_at_least_n_backtrace_lines'",
 "manufacture_backtraces.rb:3:in `raise_error_with_at_least_n_backtrace_lines'",
 "manufacture_backtraces.rb:3:in `raise_error_with_at_least_n_backtrace_lines'",
 "manufacture_backtraces.rb:3:in `raise_error_with_at_least_n_backtrace_lines'",
 "manufacture_backtraces.rb:3:in `raise_error_with_at_least_n_backtrace_lines'",
 "manufacture_backtraces.rb:3:in `raise_error_with_at_least_n_backtrace_lines'",
 "manufacture_backtraces.rb:3:in `raise_error_with_at_least_n_backtrace_lines'",
 "manufacture_backtraces.rb:3:in `raise_error_with_at_least_n_backtrace_lines'",
 "manufacture_backtraces.rb:11:in `demo'",
 "manufacture_backtraces.rb:19:in `<main>'"]