Rest for one restart bug.

restforbug.erl

-module(restforbug).

-export([start/0]).

start() ->
    ok = application:start(restforbug),
    exit(whereis(restforbug_first), bye).

restforbug_app.erl

-module(restforbug_app).

-behaviour(application).

%% callbacks
-export([start/2, stop/1]).

%% callbacks

start(_StartType, _StartArgs) ->
    restforbug_sup:start_link().

stop(_State) ->
    ok.

restforbug_server.erl

-module(restforbug_server).

-behaviour(gen_server).

%% api
-export([start_link/1]).

%% callbacks
-export([init/1,
         handle_call/3,
         handle_cast/2,
         handle_info/2,
         terminate/2,
         code_change/3]).

start_link(Name) ->
    gen_server:start_link({local, Name}, ?MODULE, [], []).

init([]) ->
    true = 4 =/= ets:update_counter(restforbug, counter, {2, 1}),
    {ok, undefined}.

handle_call(_Request, _From, State) ->
    Reply = ok,
    {reply, Reply, State}.

handle_cast(_Msg, State) ->
    {noreply, State}.

handle_info(_Info, State) ->
    {noreply, State}.

terminate(_Reason, _State) ->
    ok.

code_change(_OldVsn, State, _Extra) ->
    {ok, State}.

restforbug_sup.erl

-module(restforbug_sup).

-behaviour(supervisor).

%% api
-export([start_link/0]).

%% callbacks
-export([init/1]).

%% api

start_link() ->
    supervisor:start_link({local, ?MODULE}, ?MODULE, []).

%% callbacks

init([]) ->
    ets:new(restforbug, [named_table, public]),
    ets:insert(restforbug, {counter, 0}),
    First = {restforbug_first,
             {restforbug_server, start_link, [restforbug_first]},
             permanent, 5000, worker, [restforbug_server]},
    Second = {restforbug_second,
              {restforbug_server, start_link, [restforbug_second]},
             permanent, 5000, worker, [restforbug_server]},
    {ok, {{rest_for_one, 3, 1}, [First, Second]}}.