Error when code reloader enabled

[davejlong]

Environment

• Elixir / Hex version (mix hex.info):

$ mix hex.info
Hex:    0.14.1
Elixir: 1.3.3
OTP:    19.1

Built with: Elixir 1.3.4 and OTP 18.3.4.4

• Node / NPM version (node -v) (npm -v):

$ node -v
v6.9.1
$ npm -v
3.10.8

• Operating system:

$ uname -a
Darwin Compe.local 16.1.0 Darwin Kernel Version 16.1.0: Thu Oct 13 21:26:57 PDT 2016; root:xnu-3789.21.3~60/RELEASE_X86_64 x86_64

Current behavior

When running a brand new Kitto dashboard installed from the 0.3.0 archive, opening the sample dashboard raises errors in the console:

16:10:40.726 [error] Ranch listener Kitto.Router.HTTP had connection process started with :cowboy_protocol:start_link/4 at #PID<0.1402.0> exit with reason: {{:noproc, {GenServer, :call, [nil, {:get, #Function<1.103310966/1 in Kitto.Notifier.cache/0>}, 5000]}}, {Kitto.Router, :call, [%Plug.Conn{adapter: {Plug.Adapters.Cowboy.Conn, :...}, assigns: %{}, before_send: [], body_params: %Plug.Conn.Unfetched{aspect: :body_params}, cookies: %Plug.Conn.Unfetched{aspect: :cookies}, halted: false, host: "localhost", method: "GET", owner: #PID<0.1402.0>, params: %Plug.Conn.Unfetched{aspect: :params}, path_info: ["events"], path_params: %{}, peer: {{127, 0, 0, 1}, 51690}, port: 4000, private: %{}, query_params: %Plug.Conn.Unfetched{aspect: :query_params}, query_string: "topics=text,random,buzzwords,random,convergence", remote_ip: {127, 0, 0, 1}, req_cookies: %Plug.Conn.Unfetched{aspect: :cookies}, req_headers: [{"host", "localhost:4000"}, {"connection", "keep-alive"}, {"accept", "text/event-stream"}, {"cache-control", "no-cache"}, {"user-agent", "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.75 Safari/537.36"}, {"referer", "http://localhost:4000/dashboards/sample"}, {"accept-encoding", "gzip, deflate, sdch, br"}, {"accept-language", "en-US,en;q=0.8"}], request_path: "/events", resp_body: nil, resp_cookies: %{}, resp_headers: [{"cache-control", "max-age=0, private, must-revalidate"}], scheme: :http, script_name: [], secret_key_base: nil, state: :unset, status: nil}, []]}}

No data is rendered to the dashboard.

Workaround is to disable code reloading by appending the following code to config/config.exs:

config :kitto, reload_code?: false

I've been able to replicate the error from the master branch as well.

Expected behavior

I expect to not have errors in the console from a base install.

[zorbash]

Unfortunately this seems specific to macOS and i cannot reproduce it in Linux.

Can you please try the following steps and provide feedback?

1. Set :reload_code? to false in config/config.exs
2. Start a shell using iex -S mix from within your generated dashboard app
3. Try starting :fs using the lines: https://github.com/kittoframework/kitto/blob/master/lib/kitto/code_reloader.ex#L20

• Does fs start?
• Is there any error printed?
• If you set {:fs, "0.9.2", override: true} in your mix.exs and run mix deps.get does it still fail to start?

[davejlong]

0.9.2 fails because the API is different. fs 0.9.2 doesn't have a start_link/1 method and only a subscribe/0 method.

Manually attempting to start the :fs process results in the following:

iex(1)> :fs.start_link(:default_fs)
** (EXIT from #PID<0.484.0>) an exception was raised:
    ** (UndefinedFunctionError) function :mad_repl.load_file/1 is undefined (module :mad_repl is not available)
        :mad_repl.load_file('deps/fs/priv/mac_listener')
        src/fs.erl:43: :fs.mad_file/1
        src/fs_sup.erl:27: :fs_sup.has_executable/1
        src/fs_sup.erl:17: :fs_sup.init/1
        (stdlib) supervisor.erl:294: :supervisor.init/1
        (stdlib) gen_server.erl:328: :gen_server.init_it/6
        (stdlib) proc_lib.erl:247: :proc_lib.init_p_do_apply/3

[davejlong]

Found the solution... 5HT/fs#33. Will open a PR shortly

[davejlong]

Upgrade to 2.12.0 works on my Mac.