Invalid Elixir version requirement in mix.exs file

Question

I'm trying to run mix deps.get. When I do, I get the following error:

(Mix) Invalid Elixir version requirement <version> in mix.exs file

This is my mix.exs file:

def project do
    [
      app: :app,
      version: "0.1.0",
      elixir: "1.6.6",
      elixirc_paths: elixirc_paths(Mix.env()),
      compilers: [:phoenix, :gettext] ++ Mix.compilers(),
      start_permanent: Mix.env() == :prod,
      aliases: aliases(),
      deps: deps()
    ]
  end

which seems standard. I can't find anything on the internet about this. Changing the version doesnt work, neither does excluding the elixir version field altogether.

NOTE: System details:

Erlang/OTP 21 [erts-10.3.4] [source] [64-bit] [smp:8:8] [ds:8:8:10] [async-threads:1] [hipe] [dtrace]
Mix 1.6.6 (compiled with OTP 21)
Elixir 1.6.6 (compiled with OTP 21)

From the language used I would assume it's your :elixir field, not :version. I tried reproducing (though not with a phoenix app), and it appears to work fine. However, you typically don't see :elixir locked to such a specific version. Usually you'd see something like "~> 1.6". Does it work if you try that or "~> 1.6.6" or something? — Brett Beatty
Wild guess, but try to name application something different than :app. Maybe that is the problem. — Hauleth
This is very strange, I can remove elixir and version and still mix deps.get works. — David Magalhães

Georgy Bolyuba Georgy Bolyuba · Accepted Answer · 2021-02-09T08:52:26

I see this issue when Elixir is installed form old package by simply running:

sudo apt-get install elixir

Before running that however we need to add new package repository. It is described on Elixir install page, part for Debian.

Invalid Elixir version requirement in mix.exs file

1 Answers