Erlang docs for gen_server:call/2,3 state that a call can exit with {normal, _Location} if handle_call/3 returns {stop, normal, _} without replying:

normal
{shutdown,Term}

The server stopped during the call by returning {stop,Reason,_} from its Module:handle_call/3 callback, without replying. See also stop/3.

This repository contains minimal reproducible examples (written in both Erlang and Elixir) which demonstrate that gen_server:call/2,3 can also exit with normal as the reason if handle_call/3 does return a reply and the gen_server process was stopped from within another gen_server callback (handle_info/2).

The code is provided as an Elixir project, so to run it launch an IEx session:

$ iex -S mix

Elixir example:

iex(1)> GenServerCallNormal.run()
# [...skip output...]
%{normal: 100}

Erlang example:

iex(2)> :gen_server_call_normal.run(100, 100, true)
# [...skip output...]
%{normal: 98, success: 2}

Here we performed 100 gen_server calls of which 100 exited with the normal reason for the Elixir example (and 98 for the Erlang example); the actual numbers can differ from run to run.

Interestingly enough, this behavior cannot be reproduced if we don't write to the standard output in the handle_info/2 callback:

iex(3)> GenServerCallNormal.run(puts?: false)
%{noproc: 100}
iex(4)> :gen_server_call_normal.run(100, 100, false)
%{noproc: 100}