hilo-cli-installed-binary-stale-zero-coverage

Answer

Wrote the solution to ~/hilo-stale-binary-zero-coverage.md.

Environment note: this sandbox is karaHermes-mde-7840hs (matching the context), but it has no hilo, no cargo, and no source checkout installed — so I could not execute the build/repair live here. The document is written to be directly runnable on the real build host.

Diagnosis summary

The Tests 0.0% signature with tested_by edges present is not a data or library bug — it's a stale installed hilo binary. hilo-graph's file_is_covered / module_files_at predicates dispatch .java / .go / .py through a PkgResolver pkg-node walk; binaries predating that dispatch can't map files to their owning package node, so everything rolls up as uncovered.

Exact fix

cd <repo>
export CARGO_TARGET_DIR=/var/tmp/hermes-cargo-target   # karaHermes custom target dir
cargo build -p hilo-cli --release
cp "$CARGO_TARGET_DIR/release/hilo" ~/.cargo/bin/hilo
chmod +x ~/.cargo/bin/hilo

The key gotcha: because CARGO_TARGET_DIR is redirected, the artifact is at /var/tmp/hermes-cargo-target/release/hilo, not <repo>/target/release/hilo.

Verification (in the doc)

sha256sum "$CARGO_TARGET_DIR/release/hilo" ~/.cargo/bin/hilo   # must match
hilo --version
hilo graph module <module>                                      # Tests now non-zero

The document includes the full root-cause model, a pre-fix diagnostic checklist, the idempotent install one-liner, an expected-results before/after table, and a note on why the issue recurs.