ADR-0054 gives a prediction conditioned by an expired Historic EPC the source
"expired", so reporting can tell "no EPC at all" apart from "only an expired
one". It was implemented in IngestionOrchestrator — but the pipeline that
actually runs is modelling_e2e, which predicts through its own _predict_epc and
never adopted it. Result: zero `expired` rows have ever been written, and
`epc_property.source` holds only 'lodged' and 'predicted'.
Two things kept the flavour unreachable here, and both had to go:
- _predict_epc never looked at the historic backup at all, so no prediction
was ever conditioned.
- _flush_writes passed the literal source="predicted", and _PropertyWrite had
no field to carry a flavour, so one would have been dropped before the write
even if computed.
_predict_epc now mirrors IngestionOrchestrator._predict: the expired cert's
stable attributes fill the gaps Landlord Overrides left (overrides still win
where both speak) and condition the cohort, and it returns the source alongside
the EPC. _PropertyWrite carries it; _flush_writes persists it. save_batch
already groups deletes by source family, so a mixed predicted/expired batch
clears the shared slot correctly.
Ships dark: the reader is built only when HISTORIC_EPC_S3_ROOT is set, so
without it every prediction stays plain "predicted", exactly as today.
DEFAULT_S3_ROOT names the dev bucket, so defaulting to it would have a prod
lambda silently reading dev data — Terraform sets the var per environment.
Note this also rescues properties that currently fail to model outright: an
expired cert can supply the property_type no override resolved, where today
that raises UnresolvedPropertyTypeError.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
_predict_epc returned None for three unrelated causes — unresolved
property_type, an empty same-type cohort, and a degenerate (no MAIN part)
prediction — which the handler collapsed into one generic "not predictable"
string. The SubTask output could not say which cause fired or which data to
fix.
Raise a specific PropertyNotModellableError subclass per cause, each carrying
the property's identity (property_id, uprn, postcode, portfolio_id) and
cause-specific context. The unresolved-property-type message points at the
likely missing/contradictory Landlord Override. All subclass ValueError, so the
per-property failure boundary keeps catching them and records str(exc).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
