Unable to load Bcrypt when Debugging

[deybhayden]

Running the default mix task (just compiling) results in the error below for my project. I have Erlang 20 and can run the same commands successfully from the command line. Any suggestions for this? Found another similar issue for IntelliJ - https://github.com/KronicDeth/intellij-elixir/issues/891 - he switched crypto packages, but I'd rather not do that for just editor tooling? Thanks!

** (RuntimeError) An error occurred when loading Bcrypt.
Make sure you have a C compiler and Erlang 20 installed.
If you are not using Erlang 20, either upgrade to Erlang 20 or
use version 0.12 of bcrypt_elixir.
See the Comeonin wiki for more information.
    lib/bcrypt/base.ex:14: Bcrypt.Base.init/0
    (kernel) code_server.erl:1333: anonymous fn/1 in :code_server.handle_on_load/5
(Debugger) Initialization failed because an exception was raised:
    ** (MatchError) no match of right hand side value: {:error, :on_load_failure}
        int.erl:531: anonymous fn/3 in :int.load/2
        int.erl:527: :int.load/2
        (elixir) lib/enum.ex:1255: Enum."-map/2-lists^map/1-0-"/2
        (elixir) lib/enum.ex:1255: Enum."-map/2-lists^map/1-0-"/2
        (debugger) lib/debugger/server.ex:468: ElixirLS.Debugger.Server.initialize/1

[JakeBecker]

The debugger can't handle NIFs, so you'll need to exclude modules with NIFs in your launch configuration. Try adding the option "excludeModules": ["Bcrypt.Base"] in launch.json.

[JakeBecker]

I just tried it. You actually need to do "excludeModules": [":bcrypt_nif"].

[deybhayden]

Thank you - your first suggestion worked in that the server started, but :bcrypt_nif doesn't. It looked like my phoenix server was running, but I couldn't actually hit the localhost url though.

[JakeBecker]

Hm. Being unable to hit the Phoenix endpoint may be unrelated to the NIF issue. Can you confirm whether you can debug it without the bcrypt library?

[deybhayden]

Aha, think I got it. I had to take out "startApps" from my phx.server command. I think bcrypt exclusion worked - but then after the server started, vscode froze, then I got Debug adapter process has terminated unexpectedly.

[JakeBecker]

Ah, yeah, startApps is required for Phoenix tests but breaks Phoenix server. It's tricky!

[JakeBecker]

Hm. Sorry for continuing to open and close this issue. I'm not properly awake yet.

Debugging the silent debugger failures is a pain. Can you post your code somewhere for me to look at?

[deybhayden]

I think you can close it one more time - our app has a configuration for starting the webpack dev server as well, and I was launching it too in the debugger. When I turned that off, it started working 🎉 . I'm not sure if that's a common practice or not, but we do something like BUILD_CLIENT=true mix phx.server to kick off a webpack server proc. Think that threw a wrench in everything.

[JakeBecker]

Are you launching webpack via the watchers section of your Phoenix config? It'd be good to know if that breaks the debugger.

[deybhayden]

Yes:

watchers = case {System.get_env("BUILD_CLIENT"), IEx.started?} do
  {build?, _} when build? in [nil, false] -> []
  {_, true} -> ["npm": ["run", "start-iex", cd: asset_dir]]
  {_, _}    -> ["npm": ["start", cd: asset_dir]]
end

[JakeBecker]

Got it. Thanks!

[deybhayden]

Thank you! Great project, love actually being able to run a debugger for Elixir! 🙇

[mhussa]

Sorry to do this but, I have a similar but different situation. I get this error when my code attempts to use bcrypt.

(exit) an exception was raised: (ErlangError) Erlang error: :not_loaded :erlang.nif_error(:not_loaded) (comeonin) Elixir.Comeonin.Bcrypt.erl:142: Comeonin.Bcrypt.bf_init/3 (comeonin) Elixir.Comeonin.Bcrypt.erl:166: Comeonin.Bcrypt.bcrypt/4 (comeonin) Elixir.Comeonin.Bcrypt.erl:159: Comeonin.Bcrypt.hashpw/2 (comeonin) Elixir.Comeonin.Bcrypt.erl:118: Comeonin.Bcrypt.checkpw/2

I tried both types of excludeModules, deleted .elixir_ls and _build. rebuilt it, same thing. Any ideas? Its a phoenix project using brunch.

I should add though that its an umbrella phoenix web app. I created a task: "phx.server" to start it using the umbrella dir as the "projectDir".

Thankyou for the work you've put into this btw, was amazed to see variables in an interactive editor and not iex.

[mhussa]

I upgraded my comeonin dependancy to v4.0 and got past this error. Got another issue but I'll try to work it through first this time. Thanks anyway.