[erlang-questions] Why does Dialyzer crash on this map?

[Ivan Uemlianin]

Dear All

Quick update:

Just tried this at home on my Mac, and Dialyzer Dialyzes ltu.erl with no 
problem.

The work machine that displayed the error below is a FreeBSD machine.  
Both machines run the same version of Dialyzer (2.7.2); both obvs have a 
17.x erlang but the BSD might be a bit older.

Have any minor bugs in Dialyzer been ironed out recently?

Thanks

Ivan


On 25/11/2014 15:13, Ivan Uemlianin wrote:
> Dear All
>
> Running Dialyzer on the module below crashes Dialyzer with the error 
> following:
>
> ** module
>
>     -module(ltu).
>     -export([get_map/0]).
>
>     -spec get_map() -> map().
>     get_map() ->
>         #{labels => [one, two],
>           number => 27,
>           [1,2,3] => wer,        %% ok
>           {4,5,6} => sdf,        %% ok
>           kvok => #{
>                 a => qwe,
>                 2 => asd,
>                 [1,2,3] => wer,  %% bad
>                 {4,5,6} => sdf,  %% bad
>                 "abc" => zxc
>            }
>          }.
>
> ** crash
>
>     $ dialyzer ltu.erl
>       Checking whether the PLT /home/ivan/.dialyzer_plt is 
> up-to-date... yes
>       Proceeding with analysis...
>     =ERROR REPORT==== 25-Nov-2014::14:52:50 ===
>     Error in process <0.45.0> with exit value: 
> {{case_clause,map},[{dialyzer_dataflow,find_terminals,1,[{file,"dialyzer_dataflow.erl"},{line,3451}]},{dialyzer_dataflow,find_terminals_list,3,[{file,"dialyzer_dataflow.erl"},{line,3504}]},{dialyzer_dataflow,classify_returns... 
>
>
>
>     dialyzer: Analysis failed with error:
>     {{case_clause,map},
>      [{dialyzer_dataflow,find_terminals,1,
> [{file,"dialyzer_dataflow.erl"},{line,3451}]},
>       {dialyzer_dataflow,find_terminals_list,3,
> [{file,"dialyzer_dataflow.erl"},{line,3504}]},
>       {dialyzer_dataflow,classify_returns,1,
> [{file,"dialyzer_dataflow.erl"},{line,3443}]},
>       {dialyzer_dataflow,'-state__get_warnings/2-fun-0-',7,
> [{file,"dialyzer_dataflow.erl"},{line,2908}]},
>       {lists,foldl,3,[{file,"lists.erl"},{line,1261}]},
>       {dialyzer_dataflow,state__get_warnings,2,
> [{file,"dialyzer_dataflow.erl"},{line,2934}]},
>       {dialyzer_dataflow,get_warnings,5,
> [{file,"dialyzer_dataflow.erl"},{line,142}]},
>       {dialyzer_succ_typings,collect_warnings,2,
> [{file,"dialyzer_succ_typings.erl"},{line,182}]}]}
>     Last messages in the log cache:
>       Reading files and computing callgraph... done in 0.07 secs
>       Removing edges... done in 0.00 secs
>
> If I comment out the two lines marked "%% bad", Dialyzer can check the 
> module.  nb the same key-value pairs that are bad in the nested map 
> kvok, are ok in the top-level map.
>
> Is this supposed to happen?  If so, why?
>
> With thanks and best wishes
>
> Ivan
>
>

-- 
============================================================
Ivan A. Uemlianin PhD
Llaisdy
Speech Technology Research and Development

                     ivan@REDACTED
                         @llaisdy
                          llaisdy.wordpress.com
               github.com/llaisdy
                      www.linkedin.com/in/ivanuemlianin

                         festina lente
============================================================