crash with record union type with same record name

[gomoripeti]

gradualizing module m2 results in a crash (The issue is with type rec_t/0 which is a union of record type rec from the local module and a remote type which represents a record type with the same name.)

-module(m2).

-export([f/0]).

-type rec_t() :: m1:rec_v1() | rec_v2().

-record(rec, {
    f1,
    f2 = default}).

-type(rec_v2() :: #rec{}).

-spec f() -> rec_t().
f() ->
    #rec{f1 = <<"">>}.

-module(m1).

-record(rec, {f1}).


-type(rec_v1() :: #rec{}).

-export_type([rec_v1/0]).

I get the below crash

escript: exception error: bad generator
                 {env,
                  #{{f,0} =>
                     [{type,
                       {13,8},
                       bounded_fun,
                       [{type,
                         {13,8},
                         'fun',
                         [{type,{13,8},product,[]},
                          {user_type,{13,14},rec_t,[]}]},
                        []]}]},
                  #{},#{},
                  #{module => m2,
                    records =>
                     #{rec =>
                        [{typed_record_field,
                          {record_field,0,{atom,0,f1},{atom,{8,5},undefined}},
                          {type,0,any,[]}},
                         {typed_record_field,
                          {record_field,0,{atom,0,f2},{atom,{9,10},default}},
                          {type,0,any,[]}}]},
                    types =>
                     #{{rec_t,0} =>
                        {[],
                         {type,0,union,
                          [{remote_type,0,
                            [{atom,{5,18},m1},{atom,{5,21},rec_v1},[]]},
                           {user_type,0,rec_v2,[]}]}},
                       {rec_v2,0} => {[],{type,0,record,[{atom,0,rec}]}}}},
                  false,false,true,
                  [{clauses_controls,true}],
                  30,
                  [{type,
                    {13,8},
                    bounded_fun,
                    [{type,
                      {13,8},
                      'fun',
                      [{type,{13,8},product,[]},{user_type,{13,14},rec_t,[]}]},
                     []]}]}
  in function  typechecker:'-union_var_binds/2-lc$^1/1-0-'/1 (src/typechecker.erl, line 4859)
  in call from typechecker:union_var_binds/2 (src/typechecker.erl, line 4859)
  in call from typechecker:do_type_check_expr_in/3 (src/typechecker.erl, line 2394)
  in call from typechecker:type_check_expr_in/3 (src/typechecker.erl, line 2250)
  in call from typechecker:check_clause/5 (src/typechecker.erl, line 3536)
  in call from typechecker:'-check_clauses/5-fun-0-'/4 (src/typechecker.erl, line 3441)
  in call from lists:foldl/3 (lists.erl, line 1267)
  in call from typechecker:check_clauses/5 (src/typechecker.erl, line 3439)

Gradualizer version commit a72e7f0b7e55f235fdaa944340a13e0e41bc5ee3

[erszcz]

Hi, @gomoripeti!

Thanks for the report. I checked the examples you provide with the current master branch (https://github.com/josefs/Gradualizer/commit/f647ae76b1510f6d3b367fec06dc2d68c7ede88c) and cannot reproduce the problem - no crash occurs. Could you confirm if the problem is solved for you, too?