When developing Elixir in VSCode with the ElixirLS extension, there is an issue where your elixir installation does not get detected. This happens when you have installed elixir (and erlang) with the asdf version manager, which is quite common, since there are no good repositories for elixir in debian land.
The reason for this might be that asdf gets loaded in your
*rc file but not in your
.profile, which means it appears in the terminal that elixir is accessible but when starting VSCode your path is different and still missing asdf.
The solution is then to add asdf to your
.profile file like:
You might need to logout of your session for this to take effect.