# YARD::Handlers::Ruby::MixinHandler: Undocumentable mixin: YARD::Parser::UndocumentableError

**URL:** <https://discourse.dry-rb.org/t/yard-handlers-ruby-mixinhandler-undocumentable-mixin-yard-parser-undocumentableerror/464>\
**Category:** Support\
**Created:** [February 5, 2018, 1:44am UTC](https://discourse.dry-rb.org/t/yard-handlers-ruby-mixinhandler-undocumentable-mixin-yard-parser-undocumentableerror/464 "2018-02-05T01:44:07Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![bbuchalter](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.dry-rb.org/bbuchalter/32/207_2.png) [@bbuchalter](https://discourse.dry-rb.org/u/bbuchalter)\
**Post date:** [February 5, 2018, 1:44am UTC](https://discourse.dry-rb.org/t/yard-handlers-ruby-mixinhandler-undocumentable-mixin-yard-parser-undocumentableerror/464/1 "2018-02-05T01:44:07Z")

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I’m experimenting with replacing my home-grown value objects with dry-struct, but sadly, it seems I cannot get YARD documentation to generate. Is this something I should expect?

Here are steps to reproduce:

```auto
git clone https://github.com/bbuchalter/site_check.git
cd site_check
bin/setup
yard

```

And the output:

```auto
[warn]: in YARD::Handlers::Ruby::MixinHandler: Undocumentable mixin: YARD::Parser::UndocumentableError for class SiteCheck::Types
	in file 'lib/site_check/types.rb':6:

	6: include Dry::Types.module

```

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**Author:** ![flash-gordon](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.dry-rb.org/flash-gordon/32/494_2.png) [@flash-gordon](https://discourse.dry-rb.org/u/flash-gordon)\
**Post date:** [February 5, 2018, 9:21pm UTC](https://discourse.dry-rb.org/t/yard-handlers-ruby-mixinhandler-undocumentable-mixin-yard-parser-undocumentableerror/464/2 "2018-02-05T21:21:51Z")

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Yeah, this is expected because here `.module` generates a module for you on the fly. I don’t think YARD is able to handle such things but mb @solnic knows more on the subject.

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**Author:** ![solnic](https://yyz1.discourse-cdn.com/flex031/user_avatar/discourse.dry-rb.org/solnic/32/779_2.png) [@solnic](https://discourse.dry-rb.org/u/solnic)\
**Post date:** [February 6, 2018, 5:34pm UTC](https://discourse.dry-rb.org/t/yard-handlers-ruby-mixinhandler-undocumentable-mixin-yard-parser-undocumentableerror/464/3 "2018-02-06T17:34:53Z")

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No I don’t 😕