I’m not sure how to best describe this issue, but I’ve started to notice this recently and I don’t know what changed that started to trigger it. Basically, anytime I save a controller or any .ex file (something that triggers the compiler it seems), I get the following error when the live reloader reloads the page:

[error] #PID<0.661.0> running RosWeb.Endpoint (connection #PID<0.660.0>, stream id 1) terminated
Server: localhost:4000 (http)
Request: GET /live/websocket?vsn=2.0.0
** (exit) an exception was raised:
    ** (UndefinedFunctionError) function RosWeb.Endpoint.__handler__/2 is undefined (module RosWeb.Endpoint is not available)
        (ros) RosWeb.Endpoint.__handler__(%Plug.Conn{} ...) # Edited out the two args
        (phoenix) lib/phoenix/endpoint/cowboy2_handler.ex:17: Phoenix.Endpoint.Cowboy2Handler.init/2
        (cowboy) /ros/deps/cowboy/src/cowboy_handler.erl:41: :cowboy_handler.execute/2
        (cowboy) /ros/deps/cowboy/src/cowboy_stream_h.erl:296: :cowboy_stream_h.execute/3
        (cowboy) /ros/deps/cowboy/src/cowboy_stream_h.erl:274: :cowboy_stream_h.request_process/3
        (stdlib) proc_lib.erl:249: :proc_lib.init_p_do_apply/3


[error] #PID<0.669.0> running RosWeb.Endpoint (connection #PID<0.668.0>, stream id 1) terminated
Server: localhost:4000 (http)
Request: GET /phoenix/live_reload/socket/websocket?vsn=2.0.0
** (exit) an exception was raised:
    ** (UndefinedFunctionError) function RosWeb.Endpoint.__handler__/2 is undefined (module RosWeb.Endpoint is not available)
        (ros) RosWeb.Endpoint.__handler__(%Plug.Conn{} ...) # Edited out the two args
        (phoenix) lib/phoenix/endpoint/cowboy2_handler.ex:17: Phoenix.Endpoint.Cowboy2Handler.init/2
        (cowboy) ros/deps/cowboy/src/cowboy_handler.erl:41: :cowboy_handler.execute/2
        (cowboy) ros/deps/cowboy/src/cowboy_stream_h.erl:296: :cowboy_stream_h.execute/3
        (cowboy) ros/deps/cowboy/src/cowboy_stream_h.erl:274: :cowboy_stream_h.request_process/3
        (stdlib) proc_lib.erl:249: :proc_lib.init_p_do_apply/3

I’m using Phoenix LiveView, but this happens outside of LiveView files as well. The websocket errors out a bunch of times before it recovers and it reloads the page just fine. It seems that this only happens in development, and only with live reloading enabled.

I’m really at a loss and don’t even know where to begin to debug this, but this throws a TON of errors in my logs while developing and is quite frustrating.

Is anyone interested in helping me figure out what’s going on? I’m happy to share code examples, but as I said, I’m having a hard time knowing what I could share that would lead to a clue to what’s going on.

Any help would be greatly appreciated. Thank you.