Build failed in the case that there is a defpelemay macro for each module.

[zacky1972]

Describe the bug Build failed in the case that there is a defpelemay for each module.

To Reproduce Steps to reproduce the behavior:

1. mix new test
2. Define Test in lib/test.ex as follows:

defmodule Test do
  alias Test.Test1
  alias Test.Test2

  @moduledoc """
  Documentation for Test.
  """

  def do_test() do
    1..1000
    |> Enum.to_list()
    |> Test1.do_test()
    |> Test2.do_test()
  end
end

3. Define Test.Test1 in lib/test/test1.ex as follows:

defmodule Test.Test1 do
  require Pelemay
  import Pelemay

  defpelemay do
    def do_test(list) do
      list |> Enum.map(& &1 * 2)
    end
  end
end

3. Define Test.Test2 in lib/test/test2.ex as follows:

defmodule Test.Test2 do
  require Pelemay
  import Pelemay

  defpelemay do
    def do_test(list) do
      list |> Enum.map(& &1 + 1)
    end
  end
end

4. mix compile will be failed in the following errors:

$ mix compile
Compiling 3 files (.ex)

== Compilation error in file lib/test/test2.ex ==
** (ArgumentError) argument error
    (stdlib) :ets.new(:nif_func, [:set, :public, :named_table])
    lib/pelemay/db.ex:10: Pelemay.Db.init/0
    expanding macro: Pelemay.defpelemay/1
    lib/test/test2.ex:5: Test.Test2 (module)

Expected behavior

The compile mix compile become successful, and iex -S mix and type following command will works:

$ iex -S mix
Erlang/OTP 22 [erts-10.5] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:1] [hipe]

Interactive Elixir (1.9.1) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> Test.do_test
[3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43,
 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 75, 77, 79, 81, 83,
 85, 87, 89, 91, 93, 95, 97, 99, 101, ...]
iex(2)> 

Screenshots None.

Desktop (please complete the following information):

• Pelemay version: 0.0.2
• Elixir & Erlang/OTP versions (elixir --version):

$ elixir --version
Erlang/OTP 22 [erts-10.5] [source] [64-bit] [smp:4:4] [ds:4:4:10] [async-threads:1] [hipe]

Elixir 1.9.1 (compiled with Erlang/OTP 22)

• OS:

macOS Mojave 10.14.6

$ uname -a
Darwin *** 18.7.0 Darwin Kernel Version 18.7.0: Tue Aug 20 16:57:14 PDT 2019; root:xnu-4903.271.2~2/RELEASE_X86_64 x86_64

• Clang Version:

$ clang --version
Apple LLVM version 10.0.1 (clang-1001.0.46.4)
Target: x86_64-apple-darwin18.7.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin

Additional context

The compile will works the following steps:

1. Make test2.ex inactive
2. mix compile
3. Make test2.ex active
4. mix compile

Perhaps, it doesn't work in the case of two or more compilation of defpelemay concurrently.