do not append test profile if already there. Note that it comes from the prv list passed to providers:create/1

src/rebar_state.erl

@@ -257,12 +257,15 @@ apply_profiles(State, Profile) when not is_list(Profile) ->
 apply_profiles(State, [default]) ->
     State;
 apply_profiles(State=#state_t{default = Defaults, current_profiles=CurrentProfiles}, Profiles) ->
+    IsTesting = lists:member(test, CurrentProfiles),
     AppliedProfiles = case Profiles of
                           %% Head of list global profile is special, only for use by rebar3
                           %% It does not clash if a user does `rebar3 as global...` but when
                           %% it is the head we must make sure not to prepend `default`
                           [global | _] ->
                               Profiles;
+                          [test] when IsTesting ->
+                              deduplicate(CurrentProfiles);
                           _ ->
                               deduplicate(CurrentProfiles ++ Profiles)
                       end,