I’m in the process of writing a NIF library application which in turn depends on a vendor’s shared lib (which has it’s own set of dependencies as well). My hope is to just keep all the various .so’s contained in /priv.

I’m using elixir_make to build my NIF’s code into it’s .so, which is also spit out into /priv by the makefile.

If I just run make, my /priv folder contains vendor.so, vendor_dep1.so, my_app_nif.so, which are all the files I would expect to be present.

I can successfully compile the elixir side of my application with: LD_LIBRARY_PATH=./priv mix compile, but I was wondering if there was a good way to set the LD_LIBRARY_PATH variable from within the project, so another user can just mix compile and it just works? Otherwise mix compile fails when compiling my nif module due to the @on_load bits normally set when writing nifs:

defmodule MyApp.Nif do
  @on_load :load_nif

  # code uglified to keep the post short
  def load_nif do
    nif_path = :my_app |> :code.priv_dir() |> List.to_string() |> Path.join("my_app_nif") |> String.to_charlist()
    :erlang.load_nif(nif_path, 0) # Fails with 'vendor.so' cannot open shared object file: No such file or directory
  end
end

Unfortunately :erlang.load_nif/2 doesn’t appear to have any options for specify additional library search paths. I’d be interested in hearing any suggestions on ways of getting around this? Short of just writing a run_me_not_mix_compile.sh script