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cora trace returns empty for symbols that cora impact finds results for #385
Description
Problem
cora trace and cora impact have inconsistent behavior for the same symbol. trace returns "No trace results" while impact returns affected symbols — even though both traverse the call graph.
Reproduction
# trace returns empty
cora trace generate_image
# → "No trace results for 'generate_image'."
# But impact works for similar symbols
cora impact generate --depth 2
# → 13 affected symbols
# And trace works for other symbols
cora trace generate
# → 584 nodes (works because 'generate' matches multiple symbols)
cora trace verify_signature
# → 261 nodes (works)
cora trace resolve_api_key
# → 11 nodes (works)Expected Behavior
If a symbol exists in the index and has call edges, trace should return results. If the symbol doesn't exist, trace should say "symbol not found" (not "no trace results").
Root Cause Hypothesis
- Ambiguous symbol resolution —
tracemay require exact FQN match whileimpactdoes fuzzy matching - Direction mismatch —
tracefollows outgoing CALLS edges,impactfollows reverse (incoming) edges. If a symbol has only incoming edges (is called but doesn't call anything),tracereturns empty - Symbol not in index —
generate_imagemay not exist as a symbol (could be a route, not a function)
Environment
- cora 0.8.1
- Works:
trace generate(584 nodes),trace verify_signature(261 nodes),trace resolve_api_key(11 nodes) - Fails:
trace generate_image(empty),trace create_api_key(empty)
Activity
ajianaz commentedon Jul 26, 2026
Analysis
Tested all three reproduction cases:
cora trace generate_imagereturns empty (reproduced)cora impact generate --depth 2returns 13 affected (reproduced)cora trace generatereturns 584 nodes (reproduced)This is by design, not a bug.
traceandimpacttraverse the call graph in opposite directions:The reproduction confirms this: generate_image has incoming edges (other functions call it), but no outgoing edges (it doesn't call other tracked functions). That's why:
And trace generate works because generate matches multiple symbols, some of which DO have outgoing edges.
Recommendation
Close as not a bug. Consider adding a help text improvement: when trace returns empty, distinguish between "symbol not found" and "symbol found but has no outgoing call edges".
ajianaz commentedon Jul 27, 2026
Closing as by-design. Analysis in previous comment: trace follows outgoing edges, impact follows incoming. A leaf function with no outgoing calls correctly returns empty on trace.