Three server-side bugs in gym Docker images affecting 19 benchmark tasks

[anchit]

We found three server-side bugs in the MCP gym Docker images that make 19 benchmark tasks impossible to complete regardless of model capability. These were discovered while running the full 649-task benchmark (enterprise_ops_gym_oracle.parquet) against the official Docker images.

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Bug 1: create_virtual_event_townhall crashes with Python TypeError (8 tasks)

Domain: Teams, Hybrid
Image: enterpriseops-gym-mcp-teams

Error:

Error calling create_virtual_event_townhall: Failed to create townhall:
schemas.virtual_event_townhall.VirtualEventTownhallResponse() argument after ** must be a mapping, not NoneType

Root cause: The townhall creation handler returns None internally, then the response constructor tries to unpack it via **None, which crashes.

Affected tasks:

• task_20251125_113335_636_7ebc1127_a4ebffe8 (teams)
• task_20251205_150335_071_464ee3e0_19d263cd (teams)
• task_20251205_192805_864_464ee3e0_91f2c02f (teams)
• task_20260106_104903_639_0154326e_81f6a68a (teams)
• task_20260108_172650_003_8e9e30d7_a1ff8588 (teams)
• task_20260108_194921_186_8e9e30d7_a087d6f8 (teams)
• task_20260109_004703_994_7ebc1127_6f97f3e9 (teams)
• task_20260114_164939_471_4d9df647_2aaff95f (hybrid)

The model calls the tool with valid arguments, but the server crashes before producing any response.

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Bug 2: create_send_as_alias returns HTTP 500 (5 tasks)

Domain: Email, Hybrid
Image: enterpriseops-gym-mcp-email

Error:

Error calling create_send_as_alias: ❌ ❌ HTTP 500: Internal Server Error

No error details returned — the server crashes with an unhandled exception.

Affected tasks:

• task_20251218_102205_211_1628b966_06687c79 (hybrid)
• task_20260107_131200_705_1628b966_84e87e0f (email)
• task_20260107_141130_029_1628b966_8e264839 (email)
• task_20260109_160851_122_911d75d7_3ece8e5e (email)
• task_20260116_064331_915_d8f93f2d_854d09b8 (hybrid)

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Bug 3: create_draft / send_message FOREIGN KEY constraint failures (6 tasks)

Domain: Email, Hybrid
Image: enterpriseops-gym-mcp-email

Error (two variants):

Variant A — threads table FK (4 tasks, all hybrid):

Error creating draft: (sqlite3.IntegrityError) FOREIGN KEY constraint failed
[SQL: INSERT INTO threads (id, user_id, snippet, ...) VALUES (?, ?, ?, ?, ?, ?)]

Occurs when userId="me" in hybrid tasks. The email gym resolves "me" to a user_id that does not exist in the seeded database's users table.

Variant B — message_labels table FK (3 tasks):

Error sending message: (sqlite3.IntegrityError) FOREIGN KEY constraint failed
[SQL: INSERT INTO message_labels (message_id, label_id) VALUES (?, ?)]

The label exists (verified by modify_message working with the same label_id immediately after), but the send_message endpoint fails when labelIds is provided in the request body. Likely a transaction ordering issue where the message is committed to message_labels before the thread/message FK chain is fully resolved.

Affected tasks:

• task_20251211_100706_985_701c5774_8d658f71 (email)
• task_20251218_103430_472_701c5774_42c99459 (hybrid)
• task_20251218_120340_971_701c5774_de18aa54 (hybrid)
• task_20251219_115208_288_701c5774_66a236f8 (hybrid)
• task_20251224_104537_197_701c5774_5c104832 (hybrid)
• task_20251225_064512_901_701c5774_964bf3bf (hybrid)

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Impact

These 19 tasks (2.9% of the benchmark) are guaranteed failures regardless of the model — the server crashes or rejects valid requests before the model can complete the task. This deflates reported scores for any model evaluated on the full benchmark.

[BAJUKA]

Thank you for pointing this out and for the detailed analysis. We are investigating this issue.