A live, auto-synced index did not converge to a clean rebuild of the same
tree — 4.3% of distinct edges wrong in both directions on this repo's own
index, overwhelmingly `calls`, which is what flow queries traverse and what
explore's file ranking weights. Silent: nothing warned, and the symptom read
as "codegraph isn't very good" rather than "this index needs rebuilding."
Two causes, and the fix needed both. Resolution binds a reference to one of
the same-named definitions PROJECT-WIDE, so a definition appearing or
vanishing changes the correct answer for references in files the sync never
touches — and those references resolved successfully once, which deletes
their unresolved_refs row, leaving nothing to revisit them with (#1240's
retry only revisits refs parked as failed). Separately, when nothing
disambiguated the candidates the winner came down to rowid, i.e. the order
files happened to be WRITTEN, which differs between a scan-order full index
and a sync that appends each file as it changes. That second one is why
re-resolution alone could not converge: re-resolving against the identical
graph still picked a different candidate.
So getNodesByName now orders by (file_path, start_line) — a property of the
code, not of the write order — and sync computes a definitionDelta and
re-opens the resolution edges whose answer it may have invalidated,
re-inserting each as the reference that created it for the orphan sweep to
bind against the post-sync graph.
The delta compares `file\0name` pairs per file rather than one name set over
the batch: a commit that adds `collect` to a new file while an unrelated
changed file already defines `collect` cancels out of a batch-wide set, and
that miss was the largest residual class in the first measurement.
Conservative where the failure modes are asymmetric — a wrong deletion is a
permanent edge loss, a missed rebind is only residual drift. Edges without a
refName stamp are never touched (nothing to restore them from), sources the
sync already re-extracted are skipped, and a per-name ceiling declines the
generic names. Edges are deleted before the sweep re-inserts, since
INSERT OR IGNORE against idx_edges_identity would otherwise keep both rows
when a reference rebinds elsewhere.
Replaying real commits of this repo through sync, then diffing against a
rebuild: 16 commits 48 -> 0; 80 commits 1,634 -> 361, with the actively
misleading direction (stale edges the index keeps asserting) 671 -> 2.
Index and sync wall-clock are unchanged; the ORDER BY costs 18% per uncached
name lookup, which never reaches wall-clock because the resolver memoizes it.
The 357-edge residual at 80 commits is one pre-existing class: refs to
generic names (`push`, `join`) parked above #1240's per-name retry ceiling,
which a rebuild resolves into cross-language garbage — a TS test file
"calling" an R method. Converging there would mean manufacturing wrong edges,
so it is left alone. And no drift metric in `codegraph status`: it cannot be
computed without the rebuild it would be recommending, and a proxy would fire
on that residual and train users to ignore it.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Colby McHenryandClaude Opus 5
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