save_semantic_cache groups nodes/edges/hyperedges by their own source_file
and the write loop skips a group whose path is a ghost (not .is_file(),
silently) or out-of-scope per the #1757 guard — but an edge or hyperedge in
an ALLOWED group that references a node id from a skipped group was still
written verbatim, so on replay (check_semantic_cache) it dangled forever.
The #1895 filter does not cover this: it cleans the in-memory merged result,
while the checkpoint writes the cache BEFORE it runs and replay bypasses it
entirely.
Fix at the cache layer (the authoritative write path): before the write
loop, compute the node ids belonging to groups that will be skipped —
mirroring BOTH skip branches — minus ids also defined in a group that will
be written (duplicate-attribution nodes must not be over-pruned). Each
written group then drops edges whose source/target is a skipped id and
hyperedges whose member list intersects them (whole-hyperedge drop,
mirroring #1895). Pruning runs on the incoming result only, so with
merge_existing=True (the llm.py checkpoint path) the prior cached entry's
valid edges survive the union untouched. Everything is gated on
allowed_source_files being provided, so unscoped callers stay
byte-identical.
Complementary hardening in build_from_json: hyperedges were copied into
G.graph["hyperedges"] verbatim without member validation, so a dangling
hyperedge reached graph.json even from a live (non-cache) extraction.
Members are now remapped via the same normalization the pairwise-edge loop
uses and pruned when they still don't resolve; a hyperedge with no
surviving member is dropped whole with a stderr warning. (Single-member
hyperedges are legal in this codebase — per-file flows in the #1574 tests —
so the drop threshold is zero survivors, not two.)
Tests: scoped save with an edge to an out-of-scope real file, the same with
a ghost source_file, whole-hyperedge drop, unscoped save preserved
byte-identically (raw cache entry compared), merge_existing keeping the
prior slice's valid edges, and build_from_json pruning a dangling hyperedge
member / dropping an all-dangling hyperedge.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
