Can not start the server

[robotcator]

I follow the Installation instruction to try to run the example. The terminal outputs that:

Erlang/OTP 21 [erts-10.2.1] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:1] [hipe] [dtrace]

escript: exception error: no match of right hand side value undefined
  in function  rebar_log:log/3 (/home/tristan/Devel/rebar3/_build/prod/lib/rebar/src/rebar_log.erl, line 96)
  in call from rebar3:handle_error/2 (/home/tristan/Devel/rebar3/_build/prod/lib/rebar/src/rebar3.erl, line 317)
  in call from escript:run/2 (escript.erl, line 758)
  in call from escript:start/1 (escript.erl, line 277)
  in call from init:start_em/1 
  in call from init:do_boot/3 
** (Mix) Could not compile dependency :erlport, "/Users/username/.mix/rebar3 bare compile --paths "/Users/username/clone/boost/gym_tcp_api/_build/dev/lib/*/ebin"" command failed. You can recompile this dependency with "mix deps.compile erlport", update it with "mix deps.update erlport" or clean it with "mix deps.clean erlport"

1. I try the suggestion like 'mix deps.compile erlport', 'mix deps.update erlport' etc, it get the same error.
2. I search the output from Google, I am not familar with mix much, so didn't get too much useful information about it.

Can you kindly help to go through it?

[zoq]

What happens if you set {:erlport, "~> 0.10.0"}, instead of {:erlport, git: "https://github.com/hdima/erlport.git"}, in https://github.com/zoq/gym_tcp_api/blob/master/mix.exs#L34

[zoq]

Updated in d1bc892. Let me know if that works for you as well.

[KimSangYeon-DGU]

@robotcator
In my case, I resolved this error by using a method @zoq mentioned. Please refer to FAQ1 in README.md.
As another solution, you can downgrade your OTP version to 20.

[robotcator]

@zoq Great, I follow your solution and it works now. Thank @KimSangYeon-DGU for the helpful suggestion too.

But can we catch up with the change of gym, for the newer version of the gym support robotic arm enviroment. I saw that Robotic Arm is in the idea list of mlpack.