NFI Backtest Engine v1.4.1
v1.4.1 is a compatibility hotfix for users running the engine on Python 3.13
or Python 3.14.
Fix
Python 3.13 changed the default rendering of empty fields in ast.dump(). The
v1.4.0 verifier therefore produced a different identity for the unchanged
long_exit_rebuy callback and safely, but incorrectly, requested an exact-lowering
review.
The verifier now serializes reviewed callback ASTs consistently across Python
3.12, 3.13, and 3.14. This is not a strategy-version or Signal-specific bypass:
real stateful callback changes continue to fail closed.
The live X7 revision e8526d8268891a34c8bc6dd2c6171e44d7ee1ab0
(v17.4.483) passes both Spot and Futures Native compatibility checks with this
fix.
Certification boundary
This hotfix changes compatibility identity normalization, not simulation semantics.
It remains a product release with combined_full_x7_certified=false. The five-year
Spot certificate remains bound to v1.0.0 and the five-year Futures certificate
remains bound to v1.1.0.
Upgrade
Run the normal installer again. It selects the v1.4.1 wheel for the current
supported platform, verifies its published SHA-256 digest, and replaces the
isolated nfi-bte installation.