Every modular workspace template repo (claude-code, hermes, langgraph,
…) was crashing on boot with:
KeyError: "Unknown runtime '<runtime>'. Available: "
Root cause: `molecule_runtime/main.py` and four other modules used
top-level imports like `from adapters import get_adapter` — a monorepo
legacy that resolved when something on sys.path had an `adapters/`
package. Standalone template repos COPY only `adapter.py` (singular) to
/app and don't ship an `adapters/` package, so this import path went
through some side-resolution that left `get_adapter` unable to see the
user's adapter. The ADAPTER_MODULE → import → getattr → issubclass
chain then silently fell through to the discovery branch and reported
"Unknown runtime".
Fix is one-line per file: `from adapters` → `from molecule_runtime.adapters`
in:
- molecule_runtime/main.py:27
- molecule_runtime/a2a_executor.py:44
- molecule_runtime/coordinator.py:20
- molecule_runtime/prompt.py:6
- molecule_runtime/builtin_tools/temporal_workflow.py:417
Tests + CI added so this regression class is caught at PR time, not at
runtime in self-hosters' clusters:
- tests/test_imports.py: parametrised import smoke for every previously
affected module + a grep guard that fails if any future change
reintroduces a top-level `from adapters` / `import adapters` line
- .github/workflows/ci.yml: runs the smoke on every PR (no CI existed
before — the publish workflow only fires on tag push)
Closes#1.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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