gistfile1.rb

@call_trace = TracePoint.new(:call) do |tp|
  Thread.current['backtraces'] ||= []
  Thread.current['backtraces'] << {
    binding: tp.binding,
    method_id: tp.method_id
  }
end

@raise_trace = TracePoint.new(:raise) do |tp|
  Thread.current['backtraces'].each do |bt|
    yourself = bt[:binding].eval('self')
    method = yourself.method(bt[:method_id])
    arguments = method.parameters.inject({}) do |args, (type, name)|
      args.update(name => (bt[:binding].eval("#{name}") rescue nil))
    end

    puts "(#{yourself.inspect})##{bt[:method_id]}:"
    arguments.each do |name, value|
      puts "  #{name} = #{value.inspect}"
    end
  end
end

def foo(x, y)
  raise
end

def bar(x, y)
  foo(y, x)
end

def baz(x, y, z)
  bar(x + z, y)
end

@call_trace.enable
@raise_trace.enable

baz(1, :ahi, 3)