Behaviors from Rebar dependencies are not recognized

[eproxus]

Describe the bug In projects using Rebar 3 with dependencies that supply a behavior, the following warning is generated:

src/module.erl:
    4:1   warning behavior thebehaviour undefined ​Compiler

To Reproduce Use a behavior from a Rebar 3 dependency.

Expected behavior Compilation should behave exactly as rebar3 compile.

Actual behavior Invalid warnings are generated.

Context

• erlang_ls version (tag/sha): Version: 0.14.0+build.1534.refc3ba39d
• Editor used: Sublime Text 4 (4102)
• LSP client used: LSP v1.2.13

[robertoaloi]

Hi @eproxus what does your erlang_ls.config file looks like? https://erlang-ls.github.io/configuration/

[eproxus]

@robertoaloi I don’t have one as far as I’m aware 😊

[robertoaloi]

Ah, then your Erlang LS experience may be suboptimal :) This is what I have for an "umbrella" project:

apps_dirs:
  - "apps/*"
deps_dirs:
  - "_build/default/lib/*"
include_dirs:
  - "apps"
  - "apps/*/include"
  - "_build/default/lib/"
  - "_build/default/lib/*/include"

[eproxus]

I successfully used this config in a normal Rebar project (which supports checkouts):

deps_dirs:
  - "_build/default/lib/*"
  - "_build/default/checkouts/*"
include_dirs:
  - "_build/default/lib/*/include"
  - "_checkouts/*/include"

I understand that Erlang LS is a general tool, but I also find it a bit odd that it doesn't work out of the box with Rebar projects (which by now are ~95% of Erlang projects?).

[gomoripeti]

good to hear it worked. To clarify, Erlang LS does not work out of the box not because it is a general tool, but because some things are not yet implemented. The keyword is "Build Server Protocol". Work on a rebar3 BSP server and BSP support in ELS is on the way, so there is hope, it will eventually work out of the box for rebar3 projects.