[erlang-bugs] Dialyzer's incorrect warning about opaque types

[Shayan Pooya]

I have these two modules:

-module(has_opaque).
-export([init/0]).

-opaque state() :: queue:queue(erlang:timestamp()).
-export_type([state/0]).

-spec init()-> state().
init() ->
    queue:new().


and:

-module(use_opaque).
-export([init/0]).

-record(state, {t :: has_opaque:state()}).

init() ->
    {ok, #state{t = has_opaque:init()}}.


Dialyzer is giving me this error message:

"""
use_opaque.erl:7: The attempt to match a term of type 'undefined' |
queue:queue({non_neg_integer(),non_neg_integer(),non_neg_integer()})
against the variable _ breaks the opaqueness of has_opaque:state()
"""

Compilation and invoking dialyzer:

compile:
        mkdir -p ebin
        erlc +debug_info -o ebin/ *.erl

dialyzer:
        dialyzer --get_warnings -Wno_return -Wunmatched_returns
-Werror_handling -r ebin/ --plt ~/.dialyzer_plt


I get this error happens in Erlang 17.1 and 17.2.2 (on Linux). But Erlang
R15B02 on OpenBSD did not complain.
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