Dialyzer Issues in Elixir Libraries

[geoffrey]

I am currently facing challenges with the Dialyzer tool while working on two Elixir libraries:

1. AnyHttp Library: This library offers a unified interface for various HTTP clients, allowing for flexibility in client selection. AnyHttp Github

2. ElasticsearchEx Library: Overview: A client designed for Elasticsearch utilizing the AnyHttp library. ElasticsearchEx Github

Issue Overview:
During the Dialyzer analysis of the ElasticsearchEx library, I encountered a complex error involving the AnyHttp library. The error includes references to unknown_function and unknown_type and presents an unusual issue regarding missing beam files. A snippet of the error message:

Could not get Core Erlang code for: elasticsearch_ex/_build/dev/lib/any_http/ebin/Elixir.AnyHttp.beam 

Example of Dialyzer run

Finding suitable PLTs Checking PLT... [:any_http, :asn1, :benchee, :compiler, :crypto, :deep_merge, :elasticsearch_ex, :elixir, :inets, :jason, :kernel, :logger, :public_key, :ssl, :ssl_verify_fun, :statistex, :stdlib, :tls_certificate_check] Looking up modules in dialyzer.plt Looking up modules in dialyxir_erlang-24.3.4.14_elixir-1.13.4.plt Finding applications for dialyxir_erlang-24.3.4.14_elixir-1.13.4.plt Finding modules for dialyxir_erlang-24.3.4.14_elixir-1.13.4.plt Checking 449 modules in dialyxir_erlang-24.3.4.14_elixir-1.13.4.plt Finding applications for dialyzer.plt Finding modules for dialyzer.plt Copying dialyxir_erlang-24.3.4.14_elixir-1.13.4.plt to dialyzer.plt Looking up modules in dialyzer.plt Checking 449 modules in dialyzer.plt Adding 324 modules to dialyzer.plt :dialyzer.run error: Analysis failed with error: Could not scan the following file(s): Could not get Core Erlang code for: elasticsearch_ex/_build/dev/lib/any_http/ebin/Elixir.Inspect.AnyHttp.Error.beam Could not get Core Erlang code for: elasticsearch_ex/_build/dev/lib/any_http/ebin/Elixir.AnyHttp.beam Could not get Core Erlang code for: elasticsearch_ex/_build/dev/lib/any_http/ebin/Elixir.AnyHttp.Utils.beam Could not get Core Erlang code for: elasticsearch_ex/_build/dev/lib/any_http/ebin/Elixir.AnyHttp.Response.beam Could not get Core Erlang code for: elasticsearch_ex/_build/dev/lib/any_http/ebin/Elixir.AnyHttp.Error.beam Could not get Core Erlang code for: elasticsearch_ex/_build/dev/lib/any_http/ebin/Elixir.AnyHttp.Client.beam Could not get Core Erlang code for: elasticsearch_ex/_build/dev/lib/any_http/ebin/Elixir.AnyHttp.Adapters.Httpc.beam Last messages in the log cache: Reading files and computing callgraph... done in 0m3.66s No :ignore_warnings opt specified in mix.exs. Using default: .dialyzer_ignore.exs. Starting Dialyzer [ check_plt: false, init_plt: 'elasticsearch_ex/priv/plts/dialyzer.plt', files: ['elasticsearch_ex/_build/dev/lib/elasticsearch_ex/ebin/Elixir.ElasticsearchEx.Api.Document.beam', 'elasticsearch_ex/_build/dev/lib/elasticsearch_ex/ebin/Elixir.ElasticsearchEx.Api.Search.beam', 'elasticsearch_ex/_build/dev/lib/elasticsearch_ex/ebin/Elixir.ElasticsearchEx.Api.Utils.beam', 'elasticsearch_ex/_build/dev/lib/elasticsearch_ex/ebin/Elixir.ElasticsearchEx.Application.beam', 'elasticsearch_ex/_build/dev/lib/elasticsearch_ex/ebin/Elixir.ElasticsearchEx.Client.beam', ...], warnings: [:unknown] ] Total errors: 6, Skipped: 0, Unnecessary Skips: 0 done in 0m0.35s lib/elasticsearch_ex/client.ex:27:unknown_function Function AnyHttp.request/5 does not exist. ________________________________________________________________________________ lib/elasticsearch_ex/client.ex:82:unknown_function Function Jason.decode!/1 does not exist. ________________________________________________________________________________ lib/elasticsearch_ex/client.ex:140:unknown_function Function Jason.encode!/1 does not exist. ________________________________________________________________________________ lib/elasticsearch_ex/ndjson.ex:24:unknown_function Function Jason.encode!/1 does not exist. ________________________________________________________________________________ lib/elasticsearch_ex/ndjson.ex:41:unknown_function Function Jason.decode!/1 does not exist. ________________________________________________________________________________ lib/elasticsearch_ex/error.ex:22:unknown_type Unknown type: AnyHttp.Response.t/0. ________________________________________________________________________________ done (warnings were emitted) Halting VM with exit status 2 

Despite verifying the presence of the beam files in the specified location, I continue to encounter this issue. Additionally, when ElasticsearchEx is utilized as a dependency in any application and Dialyzer is executed, an extensive number of errors, exceeding 1,000, are generated. These errors appear to be related to missing dependencies such as elixir and mix and much more.

Partial extract of Dialyzer errors

________________________________________________________________________________ Callback info about the Oban.Pro.Worker behaviour is not available. ________________________________________________________________________________ Callback info about the Oban.Worker behaviour is not available. ________________________________________________________________________________ Function Oban.Pro.Worker.init_stage!/2 does not exist. ________________________________________________________________________________ Function Oban.Pro.Worker.fetch_recorded/1 does not exist. ________________________________________________________________________________ Function Ecto.Changeset.add_error/3 does not exist. ________________________________________________________________________________ Function Oban.Job.new/2 does not exist. ________________________________________________________________________________ Function Oban.Pro.Worker.before_new/2 does not exist. ________________________________________________________________________________ Function Oban.Worker.merge_opts/2 does not exist. ________________________________________________________________________________ Function Oban.Pro.Worker.process/3 does not exist. ________________________________________________________________________________ Function Logger.__do_log__/4 does not exist. ________________________________________________________________________________ Function Logger.__should_log__/2 does not exist. ________________________________________________________________________________ Function Logger.__do_log__/4 does not exist. ________________________________________________________________________________ Function Logger.__should_log__/2 does not exist. ________________________________________________________________________________ 

Request for Assistance:
Given the complexity of the error messages and my attempts to resolve the issue using different Elixir versions (1.13 to 1.16) without success, I would greatly appreciate any insights or guidance you might have on resolving this issue.

Thank you by advance.

[al2o3cr]

@geoffrey

During the Dialyzer analysis of the ElasticsearchEx library,

Can you provide some more detail about the steps you took? The messages here suggest that Dialyzer’s metadata is severely confused, but it’s hard to guess how that could have happened.

[geoffrey]

Hi,

Thank you @al2o3cr for you reply.

I’ve created a branch on ElasticsearchEx with the content of .dialyzer_ignore.exs disabled. You can see the Dialyzer run here.

Warning: Function AnyHttp.request/5 does not exist. Warning: Function Jason.decode!/1 does not exist. Warning: Function Jason.encode!/1 does not exist. Warning: Function Jason.encode!/1 does not exist. Warning: Function Jason.decode!/1 does not exist. Warning: Unknown type: AnyHttp.Response.t/0. 

If you need an application with ElasticsearchEx as dependency, I can provide it later today.

Let me know if you need anything else.

[al2o3cr]

The root cause appears to be one line in AnyHttp’s configuration:

elixirc_options: [debug_info: Mix.env() == :dev], 

This setting has caused exactly the behavior you observed (“Could not get Core Erlang code for …etc…”) in other projects:

Dialyzer "Could not get Core Erlang code for"

When a dependency is installed by mix, Mix.env is normally :prod - you can change that with the env option That causes polyn’s mix.exs to omit the metadata (line 14):

I tested this locally with the chore/broken-dialyzer branch:

• Running mix dialyzer on the code as-is fails with the previously-discussed errors about missing functions.
• Commenting out the elixirc_options line in AnyHttp’s mix.exs and rebuilding from scratch (after removing _build and priv/plts) gives a successful result with no errors.

[geoffrey]

It worked!

I spent hours searching for the cause without. Actually, I thought that option was needed as it’s mentioned in some places remotely related to my error message, For instance, I found a thread where you actually provided the solution.

Thank you so much for replies and the prompt resolution.

[zetetic]

FWIW adding debug_info: [Mix.env() == :dev] to elixirc_options also broke test coverage reporting in my project, e.g.

mix test --cover

produced a report showing no modules tested and 100% coverage.

Generating cover results ... Percentage | Module -----------|-------------------------- -----------|-------------------------- 100.00% | Total 

Took quite a while to find out that was the offending line. No idea what is going on.

[christhekeele]

@zetetic

No idea what is going on.

To clarify: most mix commands run with Mix.env() == :dev. However, when running mix test, you will find that Mix.env() == :test.

So, setting debug_info: [Mix.env() == :dev] will disable debug info when running mix test --cover, which is exactly what’s needed to produce test coverage results.

Instead, try debug_info: [Mix.env() != :prod] (where :prod is the default environment for mix releases) to ensure all lower environments that are not performance-sensitive get the extra telemetry on the BEAM VM to generate meaningful debug info.