Erlang error: :noproc

[sc-yan]

get this error when usring :ram in Elixir.

iex [15:00 :: 2] > :ram.put("a", "a")
** (ErlangError) Erlang error: :noproc
    (ram 0.5.0) /xxxx/deps/ram/src/ram_kv.erl:65: :ram_kv.put/2

my setup elixir 1.15.7 erlang 25.3.2

➜   git:(master) ✗ elixir -v                                                                                                                                                                        
Erlang/OTP 25 [erts-13.2.2] [source] [64-bit] [smp:16:16] [ds:16:16:10] [async-threads:1] [jit:ns]

Elixir 1.15.7 (compiled with Erlang/OTP 24)