OAI-PMH jpcoar指定で添付ファイルがあるとエラーになる

[masao]

1.6系で確認しています。

http://localhost:8080/oai?verb=ListRecords&metadataPrefix=jpcoar を叩いたところ、500 Error になります。
undefined local variable or method 'fileset' ですので、添付ファイル付きのレコードで常にエラーになるように見えます。

ログ：

I, [2026-05-18T12:06:24.856411 #1]  INFO -- : [7a72e8d6-8362-43d1-9d94-a6a2d99c0ad3] Started GET "/oai?verb=ListRecords&metadataPrefix=jpcoar" for 172.18.0.
1 at 2026-05-18 12:06:24 +0000
I, [2026-05-18T12:06:24.857967 #1]  INFO -- : [7a72e8d6-8362-43d1-9d94-a6a2d99c0ad3] Processing by OaiController#index as HTML
I, [2026-05-18T12:06:24.858048 #1]  INFO -- : [7a72e8d6-8362-43d1-9d94-a6a2d99c0ad3]   Parameters: {"verb" => "ListRecords", "metadataPrefix" => "jpcoar"}
I, [2026-05-18T12:06:25.001618 #1]  INFO -- : [7a72e8d6-8362-43d1-9d94-a6a2d99c0ad3] Completed 500 Internal Server Error in 143ms (ActiveRecord: 34.7ms (91 queries, 20 cached) | GC: 0.0ms)
E, [2026-05-18T12:06:25.004993 #1] ERROR -- : [7a72e8d6-8362-43d1-9d94-a6a2d99c0ad3]
[7a72e8d6-8362-43d1-9d94-a6a2d99c0ad3] NameError (undefined local variable or method 'fileset' for an instance of Manifestation):
[7a72e8d6-8362-43d1-9d94-a6a2d99c0ad3]
[7a72e8d6-8362-43d1-9d94-a6a2d99c0ad3] app/models/concerns/enju_oai/oai_model.rb:54:in 'block (2 levels) in EnjuOai::OaiModel#to_jpcoar'
[7a72e8d6-8362-43d1-9d94-a6a2d99c0ad3] app/models/concerns/enju_oai/oai_model.rb:53:in 'block in EnjuOai::OaiModel#to_jpcoar'
[7a72e8d6-8362-43d1-9d94-a6a2d99c0ad3] app/models/concerns/enju_oai/oai_model.rb:31:in 'EnjuOai::OaiModel#to_jpcoar'
[7a72e8d6-8362-43d1-9d94-a6a2d99c0ad3] app/controllers/oai_controller.rb:6:in 'OaiController#index'