I2866 — Each node of a measured derive reports its fingerprint, cache status and times, and each run its critical path and peak memory
Have a measured derive report, per node, its input fingerprint, cache status, run and queue time in milliseconds, outputs and changed-output count; and per run, wall time, CPU time, critical path, subprocess count and peak memory, with cargo overhead apart from the derivation.
BLOCKED wave 1 · p2 · implementation profile · runs alone
Blocked. This issue cannot start until I2521 is done. The status is derived from that, not declared.
Objective
Have a measured derive report, per node, its input fingerprint, cache status, run and queue time in milliseconds, outputs and changed-output count; and per run, wall time, CPU time, critical path, subprocess count and peak memory, with cargo overhead apart from the derivation.
Why
Split from I2521 on 2026-10-21 (3e with a3). These were the 2026-10-18 amendment to I2521's desired state. They are new instrumentation in the crate's bench module, not a measurement of the present derive, and need a build and tests of their own.
Current state
scripts/derive records whole-stage durations only (I2521's second slice). Nothing reports per-node fingerprints, cache status or queue time, and no run reports a critical path, subprocess count or peak memory.
Desired state
A measured derive's report carries every per-node and per-run field above, and a test pins their presence and units.
Scope
- apps/majordomus-cli/src/bench
- scripts/derive
- .ai/repo/project/issues/I2866.yaml
Out of scope
- Changing what any generator writes
- Budgets or gates on the measured durations
Dependencies
Acceptance criteria
- Each node of a measured run reports its input fingerprint, cache status, run and queue time in milliseconds, outputs and changed-output count
- Each run reports wall, CPU, critical path, subprocess count and peak memory, with cargo overhead apart from the derivation
- A test fails when any of those fields is missing or carries the wrong unit
Validation
- bin/majordomus plan validate
- cargo test --manifest-path apps/majordomus-cli/Cargo.toml bench
Evidence required
- derive_node_metrics
Evidence
None recorded. Every token above needs a command or an artifact behind it before this issue can be completed; narrative is refused.
Timeline
- started
- —
- verified
- —
- completed
- —
Those three fields, the evidence above and the state of the dependencies are all the status is made of. There is no status field to disagree with them.
Canonical record: .ai/repo/project/issues/I2866.yaml. Read it back with majordomus plan show I2866.