{"record":{"id":"f9082e69901ec435","repo":"tensorflow/models","slug":"registration-key-reg-key-is-never-registered-pl","errorCode":null,"errorMessage":"registration key {reg_key} is never registered. Please make sure the {reg_key} and its library is imported and linked to the trainer binary.","messagePattern":"registration key (.+?) is never registered\\. Please make sure the (.+?) and its library is imported and linked to the trainer binary\\.","errorType":"exception","errorClass":"LookupError","httpStatus":null,"severity":"error","filePath":"official/core/registry.py","lineNumber":97,"sourceCode":"  Returns:\n    The registered function or class.\n  Raises:\n    LookupError: when reg_key cannot be found.\n  \"\"\"\n  if isinstance(reg_key, str):\n    hierarchy = reg_key.split(\"/\")\n    collection = registered_collection\n    for h_idx, entry_name in enumerate(hierarchy):\n      if entry_name not in collection:\n        raise LookupError(\n            f\"collection path {entry_name} at position {h_idx} is never \"\n            f\"registered. Please make sure the {entry_name} and its library is \"\n            \"imported and linked to the trainer binary.\")\n      collection = collection[entry_name]\n    return collection\n  else:\n    if reg_key not in registered_collection:\n      raise LookupError(\n          f\"registration key {reg_key} is never \"\n          f\"registered. Please make sure the {reg_key} and its library is \"\n          \"imported and linked to the trainer binary.\")\n    return registered_collection[reg_key]\n","sourceCodeStart":79,"sourceCodeEnd":102,"githubUrl":"https://github.com/tensorflow/models/blob/e006f5f0d534913e49c1f1dae87364039fa607e2/official/core/registry.py#L79-L102","documentation":"Error \"registration key {reg_key} is never registered. Please make sure the {reg_key} and its library is imported and linked to the trainer binary.\" thrown in tensorflow/models.","triggerScenarios":"Thrown at official/core/registry.py:97 when the library encounters an invalid state.","commonSituations":"See trigger scenarios.","solutions":[],"exampleFix":null,"handlingStrategy":null,"validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"e006f5f0d534913e49c1f1dae87364039fa607e2","analyzedAt":"2026-08-24T14:09:15.576Z","schemaVersion":2},"datasetVersion":"2026-08-24T17:17:21.512Z"}