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Fix task test teardown hanging 5s per test#3499

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jlowin merged 1 commit intomainfrom
fix/task-teardown-hang
Mar 14, 2026
Merged

Fix task test teardown hanging 5s per test#3499
jlowin merged 1 commit intomainfrom
fix/task-teardown-hang

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@jlowin jlowin commented Mar 14, 2026

Every test using task=True with the in-memory transport paid a flat 5-second penalty from the Client's move_on_after(5) timeout firing during disconnect. With 300+ task tests, this was adding 25+ minutes of pure teardown overhead to the suite.

The cause was a context manager ordering regression introduced in 8b0d016c when transports.py was split into separate files. The original code (from 5d195878) correctly nested the task group inside the lifespan, but the split flattened them into async with (tg, lifespan): which reversed the teardown order. The lifespan (Docket Worker shutdown) was trying to tear down while the task group's server run() task still held live fakeredis pub/sub subscriptions — the Worker's internal TaskGroup couldn't cancel its children because those blocking operations were still alive.

The fix restores the original nesting so the task group is fully drained before the lifespan tears down:

# Before (broken): lifespan exits first, task group second
async with (tg, lifespan):
    ...

# After (fixed): task group exits first, lifespan second
async with lifespan:
    async with tg:
        ...

Also fixes subscribe_to_task_updates() which never broke out of the execution.subscribe() loop on terminal states, keeping the async iterator alive forever.

Closes #3498

Fix context manager ordering in FastMCPTransport so the task group
(server run + subscriptions) is cancelled before the lifespan
(Docket Worker) tears down. Also break subscription loop on terminal
task states.

Closes #3498
@marvin-context-protocol marvin-context-protocol Bot added bug Something isn't working. Reports of errors, unexpected behavior, or broken functionality. tests labels Mar 14, 2026
@jlowin jlowin merged commit cedf734 into main Mar 14, 2026
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@jlowin jlowin deleted the fix/task-teardown-hang branch March 14, 2026 19:33
jlowin added a commit that referenced this pull request Mar 30, 2026
Co-authored-by: Claude Opus 4.6 <[email protected]>
Co-authored-by: Jeremiah Lowin <[email protected]>
Co-authored-by: Marvin Context Protocol <41898282+Marvin Context [email protected]>
Co-authored-by: voidborne-d <[email protected]>
Co-authored-by: marvin-context-protocol[bot] <225465937+marvin-context-protocol[bot]@users.noreply.github.com>
Co-authored-by: Claude <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: d 🔹 <[email protected]>
Co-authored-by: Jeremiah Lowin <[email protected]>
Co-authored-by: nightcityblade <[email protected]>
Co-authored-by: Claude Opus 4.6 (1M context) <[email protected]>
Co-authored-by: Claude Sonnet 4.6 <[email protected]>
Co-authored-by: Bill Easton <[email protected]>
Co-authored-by: Sumanshu Nankana <[email protected]>
Co-authored-by: Eric Robinson <[email protected]>
Co-authored-by: Martim Santos <[email protected]>
Co-authored-by: d 🔹 <[email protected]>
Co-authored-by: Matthieu B <[email protected]>
Co-authored-by: Sascha Buehrle <[email protected]>
Co-authored-by: Hakancan <[email protected]>
Co-authored-by: nightcityblade <[email protected]>
Co-authored-by: Matt Hallowell <[email protected]>
Co-authored-by: nate nowack <[email protected]>
Co-authored-by: Bill Easton <[email protected]>
Co-authored-by: Marcus Shu <[email protected]>
Co-authored-by: Rushabh Doshi <[email protected]>
Co-authored-by: AIKAWA Shigechika <[email protected]>
Co-authored-by: Jeremy Simon <[email protected]>
Co-authored-by: Miguel Miranda Dias <[email protected]>
Co-authored-by: Anthony James Padavano <[email protected]>
Co-authored-by: Mostafa Kamal <[email protected]>
Fix auto-close MRE script posting comment without closing (#3386)
Fix WorkOS token scope verification bypass 🤖 Generated with Codex (#3407)
Fix initialize McpError fallthrough 🤖 Generated with Codex (#3413)
Fix transform arg collisions with passthrough params (#3431)
Fix get_* returning None when latest version is disabled (#3439)
Fix get_* returning None when latest version is disabled (#3421)
Fix server lifespan overlap teardown (#3415)
Fix $ref output schema object detection regression (#3420)
resolved annotations (#3429)
Fix async partial callables rejected by iscoroutinefunction (#3438)
Fix async partial callables rejected by iscoroutinefunction (#3423)
fix: add version to components (#3458)
fix: use intent-based flag for OIDC scope patch in load_access_token (#3465)
Fixes #3461
fix: normalize Google scope shorthands and surface valid_scopes (#3477)
fix: resolve ty 0.0.23 type-checking errors and bump pin (#3481)
fix: shield lifespan teardown from cancellation (#3480)
fix: forward custom_route endpoints from mounted servers (#3462)
fix updates _get_additional_http_routes() to traverse providers,
Fixes #3457
fix: remove hardcoded version from CLI help text (#3456)
fix: monty 0.0.8 compatibility, drop external_functions from constructor (#3468)
fix: task test teardown hanging 5s per test (#3499)
Closes #3498
fix: validate workspace path is a directory before cursor install (#3440)
Fixes #3426
fix: handle re.error from malformed URI templates in build_regex (#3501)
fix: reject empty/OIDC-only required_scopes in AzureProvider (#3503)
fix: restrict $ref resolution to local refs only (SSRF/LFI) (#3502)
fix warnings and timeouts (#3504)
close upgrade check issue when build passes (#3505)
Closes #3484
fix: URL-encode path params to prevent SSRF/path traversal (GHSA-vv7q-7jx5-f767) (#3507)
fix: prevent path traversal in skill download (#3493)
fix: prefer IdP-granted scopes over client-requested scopes in OAuthProxy (#3492)
fix: remove unrelated transform and http.py changes from PR scope
fix: remove forced follow_redirects from httpx_client_factory calls (#3496)
fix: stop passing follow_redirects to httpx_client_factory
fix: restore follow_redirects=True for custom httpx client factories
Closes #3509
fix: CSRF double-submit cookie check in consent flow (#3519)
fix: validate server names in install commands (#3522)
fix: use raw strings for regex in pytest.raises match (#3523)
fix: reject refresh tokens used as Bearer access tokens (#3524)
fix: route ResourcesAsTools/PromptsAsTools through server middleware (#3495)
fix: resolve Pyright "Module is not callable" on @tool, @resource, @prompt decorators (#3540)
fix: filter warnings by message in KEY_PREFIX test (#3549)
fix: suppress output schema for ToolResult subclass annotations (#3548)
fix: increase sleep duration in proxy cache tests (#3567)
fix: store absolute token expiry to prevent stale expires_in on reload (#3572)
fix: preserve tool properties named 'title' during schema compression (#3582)
Fix loopback redirect URI port matching per RFC 8252 §7.3 (#3589)
Fix app tool routing: visibility check and middleware propagation (#3591)
Fix query parameter serialization to respect OpenAPI explode/style settings (#3595)
Fix dev apps form: union types, textarea support, JSON parsing (#3597)
fix(google): replace deprecated /oauth2/v1/tokeninfo with /oauth2/v3/userinfo (#3603)
fix: resolve EntraOBOToken dependency injection through MultiAuth (#3609)
fix(docs): correct misleading stateless_http header (#3622)
fix: filesystem provider import machinery (#3626)
Closes #3625 (issues 2, 3, 6)
fix: recover StdioTransport after subprocess exits (#3630)
fix(server): preserve mounted tool task metadata (#3632)
fix: scope deprecation warning filter to FastMCPDeprecationWarning (#3649)
fix imports, add PrefabAppConfig (#3650)
fix: resolve CurrentFastMCP/ctx.fastmcp to child server in mounted background tasks (#3651)
Fix blocking docs issues: chart imports, Select API, Rx consistency (#3652)
closed by default (#3657)
Fix prompt caching middleware missing wrap/unwrap round-trip (#3666)
fix: serialize object query params per OpenAPI style/explode rules (#3662)
Fixes #2857
fix: HTTP request headers not accessible in background task workers (#3631)
fix: restore HTTP headers in worker execution path for background tasks (#3681)
fix: strip discriminator after dereferencing schemas (#3682)
fix: remove stale ty:ignore directives for ty 0.0.26 (#3684)
Fix docs gaps in app provider pages (#3690)
fix: dev apps log panel UX improvements (#3698)
fix dev server empty string args (#3700)
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Task tests take ~5s each due to teardown ordering bug in FastMCPTransport

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