Loader wants to manage directory which is already managed

[jcoyne]

I have two gems. One called dor-services which knows nothing of zeitwerk and one called dor-services-client. The latter is a dependency of the former. The latter does use zeitwerk. When I run tests for dor-services I now get:

Failure/Error: require 'dor/services/client'

Zeitwerk::Error:
  loader

  #<Zeitwerk::Loader:0x00007fdd1e44f2e8
   @autoloaded_dirs=[],
   @autoloads={},
   @eager_load_exclusions=#<Set: {}>,
   @eager_loaded=false,
   @ignored=#<Set: {}>,
   @ignored_paths=#<Set: {}>,
   @inflector=#<DorServicesClientInflector:0x00007fdd1e44ef78>,
   @initialized_at=2019-05-23 15:53:38 -0500,
   @lazy_subdirs={},
   @logger=nil,
   @mutex=#<Thread::Mutex:0x00007fdd1e44efc8>,
   @mutex2=#<Thread::Mutex:0x00007fdd1e44efa0>,
   @preloads=[],
   @reloading_enabled=false,
   @root_dirs={},
   @setup=false,
   @shadowed_files=#<Set: {}>,
   @tag="1157b8",
   @to_unload={}>


  wants to manage directory /Users/jcoyne85/workspace/sul-dlss/dor-services/lib, which is already managed by

  #<Zeitwerk::Loader:0x00007fdd1d887c30
   @autoloaded_dirs=[],
   @autoloads=
    {"/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/tasks"=>
      [Object, :Tasks],
     "/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/dor/indexers"=>
      [Dor, :Indexers],
     "/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/dor/exceptions.rb"=>
      [Dor, :Exceptions],
     "/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/dor/utils"=>
      [Dor, :Utils],
     "/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/dor/models"=>
      [Dor, :Models],
     "/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/dor/workflow"=>
      [Dor, :Workflow],
     "/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/dor/release_tags.rb"=>
      [Dor, :ReleaseTags],
     "/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/dor/config.rb"=>
      [Dor, :Config],
     "/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/dor/version.rb"=>
      [Dor, :Version],
     "/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/dor/services"=>
      [Dor, :Services],
     "/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/dor/datastreams"=>
      [Dor, :Datastreams]},
   @eager_load_exclusions=#<Set: {}>,
   @eager_loaded=false,
   @ignored=#<Set: {}>,
   @ignored_paths=#<Set: {}>,
   @inflector=#<DorServicesClientInflector:0x00007fdd1d8877a8>,
   @initialized_at=2019-05-23 15:53:37 -0500,
   @lazy_subdirs=
    {"Tasks"=>["/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/tasks"],
     "Dor::Indexers"=>
      ["/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/dor/indexers"],
     "Dor::Utils"=>
      ["/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/dor/utils"],
     "Dor::Models"=>
      ["/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/dor/models"],
     "Dor::Workflow"=>
      ["/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/dor/workflow"],
     "Dor::ReleaseTags"=>
      ["/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/dor/release_tags"],
     "Dor::Services"=>
      ["/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/dor/services"],
     "Dor::Datastreams"=>
      ["/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/dor/datastreams"]},
   @logger=nil,
   @mutex=#<Thread::Mutex:0x00007fdd1d8877f8>,
   @mutex2=#<Thread::Mutex:0x00007fdd1d8877d0>,
   @preloads=[],
   @reloading_enabled=false,
   @root_dirs={"/Users/jcoyne85/workspace/sul-dlss/dor-services/lib"=>true},
   @setup=false,
   @shadowed_files=
    #<Set: {"/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/dor/certificate_authenticated_rest_resource_factory.rb",
     "/Users/jcoyne85/workspace/sul-dlss/dor-services/lib/dor/rest_resource_factory.rb"}>,
   @tag="8029fe",
   @to_unload={}>

[fxn]

Hey!

I don't fully understand the situation. Let me ask you some questions.

I understand from the description that dor-services-client uses Zeitwerk, and dor-services does not. I also understand that dor-services depends on dor-services-client. So, at some point dor-services performs a require of some file from dor-services-client that defines its loader. Is that all right?

If yes, I do not get why the configured loader above has a root directory .../sul-dlss/dor-services/lib. That directory does not seem right for dor-services-client. Which is the explanation for that?

Can you also share the source code that instantiates and configures the Zeitwerk loader, and where is it located?

[jcoyne]

I think the problem was that we made our lib a relative require by zeitwerk. Making it an absolute path seems to have fixed the issue: https://github.com/sul-dlss/dor-services-client/pull/65/files

[fxn]

Oh yes, that is something to be careful about in gems.

Glad you found it.