Measured through the real pipeline, not the unit tests: a Rust job goes from
186s to 84s (build phase 150s -> 47s), and 75s with the source modified, which
is the scenario CI actually runs. The entry is 645 MB and costs 8s to restore.
The test that decides whether this ships is row 4: a deliberate type error in
fury-core, built warm. The cache restored 645 MB of dependencies and the build
still went red with E0308, exit 1, publishing nothing. A cache that can turn a
red build green is the worst failure a CI system has because it is silent --
re-run that row whenever the prune rules change.
AGENTS.md #17 records something found while validating: `vmrun list` is
per-user. Run as the wrong user it answers "Total running VMs: 0" while a clone
is very much alive, which makes the "no VMs running" check before a
deploy --force (#14) unreliable. `ps | grep vmware-vmx` is user-independent and
was already the recommended diagnosis.
Measured first, as thread entry #12 requires: a cold furyrs pipeline is 134.7s,
target/ is 3.0 GiB raw and 2.5 GiB pruned, and the stored entry is 645 MiB. A
warm job pays 8.1s (upload + extract) to skip ~120s of dependency compilation.
Publishing costs 15.7s but only on a miss. Build it.
The assertion in the plan turned out to be worthless and is replaced. It
re-scanned for */.fingerprint/<member>-* after deleting exactly those paths, so
asked to catch a planted fury-core fingerprint it exited 0 -- the prune had
removed the evidence before the check looked. An assertion sharing its globs
with the deletion can only prove that rm ran; it cannot see the failure that
matters, which is a glob that never matched the artifact in the first place.
The replacement asks a different oracle. Cargo records in each .d depfile the
sources an artifact was built from: dependencies point into the registry,
anything built from workspace source points back into the workspace. After a
correct prune, zero surviving depfiles reference workspace source outside
target/. Verified negatively too -- an artifact named totallyunrelated-abc123.d
that no prune glob matches, declaring a dependency on fury-core/src/lib.rs,
makes the script exit 2 and refuse to publish.
zstd is already present on the template, so no rebuild is needed; the gzip
fallback stays for the plain LinuxBuild2404.
Simone