Cannot compile :rl

[conorfoley]

When starting a new API project, the github dependency :rl cannot compile.

GEN    clean
 
ERLC   rl.erl rl_app.erl rl_server.erl rl_sup.erl

compile: warnings being treated as errors

src/rl_server.erl:158: erlang:get_stacktrace/0 used following an old-style 'catch' may stop working in a future release. (Use it inside 'try'.)

src/rl_server.erl:200: erlang:get_stacktrace/0 used following an old-style 'catch' may stop working in a future release. (Use it inside 'try'.)

make: *** [ebin/rl.app] Error 1

** (Mix) Could not compile dependency :rl, "make clean && make" command failed. You can recompile this dependency with "mix deps.compile rl", update it with "mix deps.update rl" or clean it with "mix deps.clean rl"

I'm running Elixir v1.5.2 and Erlang/OTP 20 [erts-9.1.3].