Always seed the random generator before Enum.rand/:rand/

[sirn]

Erlang by default do not use cryptographically strong seed for its random generator. This can result in generating a random number that could be predicted. This also applies to Enum.random, as it also use :rand internally.

See also https://hashrocket.com/blog/posts/the-adventures-of-generating-random-numbers-in-erlang-and-elixir

---

Additionally, all use of :random is a no-no:

Pyxis ~ $ erl
Erlang/OTP 21 [erts-10.3.2] [source] [64-bit] [smp:2:2] [ds:2:2:10] [async-threads:1] [hipe]

Eshell V10.3.2  (abort with ^G)
1> random:uniform().
0.4435846174457203
2>
User switch command
 --> q
Pyxis ~ $ erl
Erlang/OTP 21 [erts-10.3.2] [source] [64-bit] [smp:2:2] [ds:2:2:10] [async-threads:1] [hipe]

Eshell V10.3.2  (abort with ^G)
1> random:uniform().
0.4435846174457203
2>