backend redefine warnings

[ayrat555]

I compile my app with compile --warnings-as-errors

If I use any of the backends, for example ex_cldr_units. I'm getting

warning: redefining module BlockScoutWeb.Cldr.Number (current version loaded from /home/ayrat/Development/rockn/blockscout/_build/dev/lib/block_scout_web/ebin/Elixir.BlockScoutWeb.Cldr.Number.beam)
  lib/block_scout_web/cldr.ex:

which fails compilation

[kipcole9]

Thanks for the report. Can you let me know:

1. The version of ex_cldr and of the dependent packages you are using?
2. An example backend configuration module that reports the error?
3. The warning is always on *.Cldr.Number ?

That way I can build a simple test case to see how the issue arises.

[ayrat555]

1. {:ex_cldr, "~> 2.0"} -> 2.7.0
2. dependent package is {:ex_cldr_units, "~> 2.5"} configuration module

   defmodule BlockScoutWeb.Cldr do
   use Cldr,
   default_locale: "en",
   locales: ["en"],
   gettext: BlockScoutWeb.Gettext,
   generate_docs: false
   end

3. yes

[kipcole9]

Thanks much, I'll work on this over the next 12 hours. Sorry for the inconvenience.

[kipcole9]

May I also suggest update to ex_cldr version 2.7.2 which fixes an issue related to Gettext configuration in ex_cldr backend modules.

[ayrat555]

I tried it with no success

[kipcole9]

Hmmm, I'm not seeing the same symptoms as you. I have created the simplest repo I can at https://github.com/elixir-cldr/cldr_issue_130

If you have an opportunity, could you clone it and compile and see if you are getting the same warning result? I hard coded the current releases to be deterministic. I also added:

use Cldr,
  ...
  providers: [Cldr.Number, Cldr.Unit]

Although removing it has no noticeable difference other than silencing some console logging at compiler time.

[ayrat555]

cldr_issue_130 is compiling without any warnings. I tried setting exactly the same deps versions but again the warning appears. Also, I tried to configure the library with otp_app option. no success.

Maybe the issue is related to umbrella applications?

[kipcole9]

Any possibility you can give me access to your repo? I appreciate the answer may be "no" for confidentiality reasons, but it would certainly make it easier for me to work on the issue. I can't think of why an umbrella app would make a difference.

[ayrat555]

no problem. it's here https://github.com/poanetwork/blockscout/pull/2473

[kipcole9]

I believe the issue is that you are defining your own BlockScoutWeb.Cldr.Number module in block_scout_web/views/cldr/number.ex. This clashes with the generated module that comes from

defmodule BlockScoutWeb.Cldr do
  use Cldr,
    default_locale: "en",
    locales: ["en"],
    gettext: BlockScoutWeb.Gettext,
    generate_docs: false,
    providers: [Cldr.Number, Cldr.Unit]
end

You note that you see a bug in Cldr.Number.to_string!/3. Let me know what the wrong behaviour is and I'll work on fixing that. A failing example would be a big help.

In general it is best to not create modules under the namespace of the Cldr backend module. That is, don't create any module that starts with BlockScoutWeb.Cldr in this case. I will update the documentation to make a note of that.

[kipcole9]

I also recommend changing

config :ex_cldr,
  default_locale: "en",
  locales: ["en"],
  gettext: BlockScoutWeb.Gettext

to

config :ex_cldr,
  default_locale: "en"

in apps/config/config.exs

[kipcole9]

Oh, I see that your private BlockScoutWeb.Cldr.Niumber module was working around some old dialyzer errors. ex_cldr and friends now all pass dialyzer so I wouldn't expect you to need this module any more.

[ayrat555]

@kipcole9 thanks. the issue was in the conflicting module name. renaming it fixed the issue