Add Mix.install/2

[wojtekmach]

Proposal: https://groups.google.com/g/elixir-lang-core/c/q0k2dX992HU

[josevalim]

💚 💙 💜 💛 ❤️

[wojtekmach]

I noticed the following:

# ecto_test.exs
Mix.install([
  :ecto
])

import Ecto.Query
IO.inspect(from(p in "posts"))

~% elixir ecto_test.exs
** (CompileError) ecto_test.exs:5: module Ecto.Query is not loaded and could not be found
    (elixir 1.12.0-dev) lib/code.ex:928: Code.require_file/2

it's easy to work around it:

# ecto_test.exs
Mix.install([
  :ecto
])

defmodule Main do
  def main do
    import Ecto.Query
    IO.inspect(from(p in "posts"))
  end
end

Main.main()
# Outputs: #Ecto.Query<from p0 in "posts">

but I'm curious if there's anything we can do about it.