Twine is a tracing tool based on Ferd's wonderful recon_trace.

recon_trace is great for providing a safe way to debug live BEAM systems, but can be a little unweildy, especially on Elixir systems. Twine is a wrapper for recon_trace, and adds a familiar, friendly, syntax.

In a remote shell for your running process,

require Twine

Twine.print_calls(MyModule.my_function(_arg1, _arg2), 3)

Just like recon_trace, this will print the first three calls to MyModule.my_function/2, but will do so in Elixir syntax.

You can even match specific calls by using pattern matching. This will print all calls to handle_call for the :ping call.

require Twine

Twine.print_calls(MyModule.handle_call(:ping, _from, _state), 3)

More details are provided in the hex docs.

def deps do
  [
    {:twine, "~> 0.4.0"}
  ]
end