Issue
User: Dev User (dev@example.com)
Student message: Error creating question variant
Instructor message: CourseIssueError: /PrairieLearn/testCourse/questions/brokenGeneration/server.py: Error calling generate(): Error: CodeCallerNative child process exited unexpectedly, code = 1, signal = null
ID: 49
Date: 2026-08-04 21:54:07 (CDT)

  • Console log:

    Traceback (most recent call last)
/PrairieLearn/testCourse/questions/brokenGeneration/server.py:2 in generate
  1 def generate(_data):
❱ 2     raise RuntimeError("deliberately broken generate function")
  3 
RuntimeError: deliberately broken generate function

  • Associated data: 

    {
    "course": {
        "id": "3",
        "path": "/PrairieLearn/testCourse",
        "title": "Test Course",
        "branch": "master",
        "options": {
            "devModeFeatures": {}
        },
        "created_at": {},
        "deleted_at": null,
        "repository": null,
        "short_name": "QA 101",
        "commit_hash": null,
        "sync_errors": null,
        "draft_number": 0,
        "json_comment": null,
        "sharing_name": null,
        "sharing_token": "3e5150cf-26fa-4a2c-8ea3-9dcb9754e124",
        "sync_warnings": "",
        "example_course": false,
        "institution_id": "1",
        "template_course": false,
        "display_timezone": "America/Chicago",
        "announcement_html": null,
        "announcement_color": null,
        "show_getting_started": false,
        "sync_job_sequence_id": null,
        "yearly_enrollment_limit": null,
        "questions_receive_user_data": true,
        "course_instance_enrollment_limit": null,
        "ai_grading_free_credit_redemptions_used": 0
    },
    "variant": {
        "id": "2302",
        "date": {},
        "open": true,
        "broken": true,
        "number": 1,
        "params": {},
        "options": {},
        "team_id": null,
        "user_id": "1",
        "duration": 0,
        "broken_at": {},
        "broken_by": null,
        "course_id": "3",
        "num_tries": 0,
        "modified_at": {},
        "preferences": {},
        "question_id": "198",
        "true_answer": {},
        "variant_seed": "mhjo4t",
        "workspace_id": null,
        "authn_user_id": "1",
        "first_duration": null,
        "course_instance_id": "3",
        "instance_question_id": null,
        "client_fingerprint_id": null
    },
    "question": {
        "id": "198",
        "qid": "brokenGeneration",
        "type": "Freeform",
        "uuid": "a2f12dbe-e030-4782-87aa-713d61728539",
        "draft": false,
        "title": "Broken generation function",
        "number": 297,
        "options": null,
        "topic_id": "33",
        "course_id": "3",
        "directory": "brokenGeneration",
        "deleted_at": null,
        "sync_errors": null,
        "client_files": [
            "client.js",
            "question.html",
            "answer.html"
        ],
        "dependencies": {},
        "json_comment": null,
        "sync_warnings": "",
        "grading_method": "Internal",
        "partial_credit": true,
        "share_publicly": false,
        "single_variant": false,
        "workspace_args": null,
        "workspace_home": null,
        "workspace_port": null,
        "workspace_image": null,
        "preferences_schema": null,
        "template_directory": null,
        "show_correct_answer": true,
        "sync_job_sequence_id": null,
        "share_source_publicly": false,
        "workspace_environment": {},
        "workspace_url_rewrite": null,
        "external_grading_files": [],
        "external_grading_image": null,
        "json_workspace_comment": null,
        "workspace_graded_files": [],
        "external_grading_timeout": null,
        "external_grading_entrypoint": null,
        "workspace_enable_networking": false,
        "external_grading_environment": {},
        "json_external_grading_comment": null,
        "external_grading_enable_networking": false
    }
}

  • System data: 

    {
    "stack": "CourseIssueError: /PrairieLearn/testCourse/questions/brokenGeneration/server.py: Error calling generate(): Error: CodeCallerNative child process exited unexpectedly, code = 1, signal = null\n    at processQuestionServer (file:///PrairieLearn/apps/prairielearn/dist/question-servers/freeform.js:503:27)\n    at process.processTicksAndRejections (node:internal/process/task_queues:104:5)\n    at async instrumentedWithMetrics (file:///PrairieLearn/packages/opentelemetry/dist/metrics.js:47:16)\n    at async file:///PrairieLearn/apps/prairielearn/dist/question-servers/freeform.js:623:56\n    at async withCodeCaller (file:///PrairieLearn/apps/prairielearn/dist/lib/code-caller/index.js:159:20)\n    at async file:///PrairieLearn/apps/prairielearn/dist/question-servers/freeform.js:622:16\n    at async file:///PrairieLearn/packages/opentelemetry/dist/tracing.js:7:28\n    at async makeVariant (file:///PrairieLearn/apps/prairielearn/dist/lib/question-variant.js:43:36)\n    at async makeAndInsertVariant (file:///PrairieLearn/apps/prairielearn/dist/lib/question-variant.js:162:52)\n    at async ensureVariant (file:///PrairieLearn/apps/prairielearn/dist/lib/question-variant.js:263:12)\n    at async file:///PrairieLearn/apps/prairielearn/dist/lib/question-render.js:293:20\n    at async getAndRenderVariant (file:///PrairieLearn/apps/prairielearn/dist/lib/question-render.js:277:21)\n    at async file:///PrairieLearn/apps/prairielearn/dist/pages/instructorQuestionPreview/instructorQuestionPreview.js:49:5",
    "courseErrData": {
        "stack": "Error\n    at CodeCallerNative._errorData (file:///PrairieLearn/apps/prairielearn/dist/lib/code-caller/code-caller-native.js:533:29)\n    at CodeCallerNative._callCallback (file:///PrairieLearn/apps/prairielearn/dist/lib/code-caller/code-caller-native.js:460:29)\n    at CodeCallerNative._handleChildExit (file:///PrairieLearn/apps/prairielearn/dist/lib/code-caller/code-caller-native.js:374:18)\n    at ChildProcess.emit (node:events:509:28)\n    at ChildProcess._handle.onexit (node:internal/child_process:295:12)",
        "outputBoth": "\u001b[2mTraceback \u001b[0m\u001b[1;2m(\u001b[0m\u001b[2mmost recent call last\u001b[0m\u001b[1;2m)\u001b[0m\n\u001b[2m/PrairieLearn/testCourse/questions/brokenGeneration/\u001b[0m\u001b[1mserver.py\u001b[0m:2 in generate\n  \u001b[2m1 \u001b[0m\u001b[94mdef\u001b[0m\u001b[90m \u001b[0m\u001b[92mgenerate\u001b[0m(_data):\n\u001b[31m❱ \u001b[0m2     \u001b[1;4;94mraise\u001b[0m\u001b[1;4m \u001b[0m\u001b[1;4;96mRuntimeError\u001b[0m\u001b[1;4m(\u001b[0m\u001b[1;4;33m\"\u001b[0m\u001b[1;4;33mdeliberately broken generate function\u001b[0m\u001b[1;4;33m\"\u001b[0m\u001b[1;4m)\u001b[0m\n  \u001b[2m3 \u001b[0m\n\u001b[1;91mRuntimeError: \u001b[0mdeliberately broken generate function\n",
        "outputData": "",
        "childIsNull": true,
        "lastCallData": {
            "cwd": "/PrairieLearn/testCourse/questions/brokenGeneration",
            "fcn": "generate",
            "args": [
                {
                    "params": {},
                    "options": {
                        "user": {
                            "uid": "dev@example.com",
                            "uin": "000000000",
                            "name": "Dev User"
                        },
                        "group": null,
                        "question_path": "/PrairieLearn/testCourse/questions/brokenGeneration",
                        "course_extensions_path": "/PrairieLearn/testCourse/elementExtensions",
                        "client_files_course_path": "/PrairieLearn/testCourse/clientFilesCourse",
                        "server_files_course_path": "/PrairieLearn/testCourse/serverFilesCourse",
                        "client_files_question_path": "/PrairieLearn/testCourse/questions/brokenGeneration/clientFilesQuestion"
                    },
                    "preferences": {},
                    "variant_seed": 1359727085,
                    "correct_answers": {}
                }
            ],
            "file": "server",
            "paths": [
                "/PrairieLearn/apps/prairielearn/python",
                "/PrairieLearn/testCourse/serverFilesCourse"
            ],
            "forbidden_modules": []
        },
        "outputStderr": "\u001b[2mTraceback \u001b[0m\u001b[1;2m(\u001b[0m\u001b[2mmost recent call last\u001b[0m\u001b[1;2m)\u001b[0m\n\u001b[2m/PrairieLearn/testCourse/questions/brokenGeneration/\u001b[0m\u001b[1mserver.py\u001b[0m:2 in generate\n  \u001b[2m1 \u001b[0m\u001b[94mdef\u001b[0m\u001b[90m \u001b[0m\u001b[92mgenerate\u001b[0m(_data):\n\u001b[31m❱ \u001b[0m2     \u001b[1;4;94mraise\u001b[0m\u001b[1;4m \u001b[0m\u001b[1;4;96mRuntimeError\u001b[0m\u001b[1;4m(\u001b[0m\u001b[1;4;33m\"\u001b[0m\u001b[1;4;33mdeliberately broken generate function\u001b[0m\u001b[1;4;33m\"\u001b[0m\u001b[1;4m)\u001b[0m\n  \u001b[2m3 \u001b[0m\n\u001b[1;91mRuntimeError: \u001b[0mdeliberately broken generate function\n",
        "outputStdout": "",
        "outputRestart": "",
        "callbackIsNull": false,
        "timeoutIDIsNull": true
    }
}

Broken generation function

Broken question due to error in question code

Correct answer

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Question

QID:
Title:
Broken generation function

Variant

Started at:
2026-08-04 21:54:07 (CDT)
Duration:
0s
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