PyCodeKG v0.26.0

Release Notes — v0.26.0

Released: 2026-09-06

This release removes a fragile pattern from snapshot handling and fixes a
crash in dependency analysis. Both were found while retiring a class of bug
that had already shipped twice this month.

What changed

The Snapshot subclass is gone. PyCodeKG used to subclass the shared
kg_utils.snapshots.Snapshot to expose metrics, vs_previous, and
vs_baseline as typed properties instead of plain dicts. That forced a
hand-written copy of nine manager methods — capture, save_snapshot,
load_snapshot, get_previous, get_baseline, diff_snapshots,
_compute_delta, to_dict, and from_dict — and one of those copies is what
dropped the snapshot key and provenance fields in 0.25.0, patched same-day in
0.25.1. Removing the subclass removes the whole class of bug instead of the
one instance of it: those methods and the Snapshot class itself are gone,
and the shared implementations run unmodified.

A snapshot's metrics, vs_previous, and vs_baseline are now plain dicts.
SnapshotMetrics and SnapshotDelta remain available as converters for code
that wants attribute access — metrics_from_dict(snap.metrics).total_nodes
instead of snap.metrics.total_nodes. Snapshot files, manifests, CLI output,
and the snapshot_show / snapshot_diff MCP tools are unchanged.

A stale graph can no longer crash dependency analysis. The property-family
detector used a line number from the knowledge graph to index into the current
source file. If the graph was older than the working tree — the normal state
between an edit and a rebuild — a shortened file could put that index past the
end of the list, raising an IndexError and aborting the whole analysis phase
instead of returning a wrong answer. It now treats an out-of-range line number
as "not a property," so a stale graph degrades gracefully instead of crashing.

The delta-backfill fix in kgmodule-utils 0.19.1 now reaches PyCodeKG.
Loading a saved snapshot previously reported coverage_delta and
critical_issues_delta as absent even though list_snapshots() and
diff_snapshots() computed them correctly for the same pair — the read path
that snapshot show uses was the one giving the wrong answer. With the
kgmodule-utils floor resolving to 0.19.1, snapshot show now reports the
same numbers as every other view of a snapshot.

Upgrading

No action required for normal use — snapshot files, the CLI, and the MCP
tools are unchanged. If your code accessed Snapshot.metrics as an object
with attributes (snap.metrics.total_nodes), switch to dict access
(snap.metrics["total_nodes"]) or call metrics_from_dict(snap.metrics) for
the old style with attribute access.

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Full changelog: CHANGELOG.md