The existing wheel-publish smoke (`wheel_smoke.py`) only IMPORTS
`molecule_runtime.main` at module scope. Lazy imports buried inside
`async def execute(...)` bodies (e.g. `from a2a.types import FilePart`)
NEVER evaluate at static-import time — they crash at first message
delivery in production.
The 2026-04-2x v0→v1 a2a-sdk migration shipped 5 such regressions in
templates that all looked fine at module-load smoke. This change adds
`smoke_mode.py` plus a `MOLECULE_SMOKE_MODE=1` short-circuit in
`main.py`: after `adapter.create_executor(...)`, the boot path invokes
`executor.execute(stub_ctx, stub_queue)` once with a 5s timeout
(`MOLECULE_SMOKE_TIMEOUT_SECS`). Healthy import tree → execution
proceeds far enough to hit a network boundary and times out (exit 0).
Broken lazy import → `ImportError` / `ModuleNotFoundError` from inside
the executor body (exit 1). Other downstream errors (auth, validation)
pass — those are caught by adapter-level tests, not this gate.
Stub `(RequestContext, EventQueue)` is built from the real a2a-sdk so
SendMessageRequest/RequestContext constructor changes also surface as
import-tree failures (the regression class also includes "SDK
refactored mid-publish"). The stub-build itself is wrapped — if it
raises, that's a smoke fail too.
Phase 2 (separate PR, molecule-ci) wires this into
publish-template-image.yml so the publish gate runs the boot smoke
against every template image before pushing the tag.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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