v2.1.0 — read what the tool was handed

Thirteen findings, all reported against 2.0.0 with a measured reproduction.
Most of them reduce to one shape: something was consumed on a contract other
than the one it is written to, and the mismatch was reported as a fault of
whatever it was pointed at.

Changed

• The lockstep pins move to reconverge 0.5.0, at every recorded site.
  2.0.0 moved the gate to 0.4.0 and updated four of the six the policy
  names, so rust-toolchain.toml, CONTRIBUTING.md and pins.yml still
  recorded 0.1.11 — and pins.yml measures upstream drift against its own
  RECONVERGE_PIN, so its weekly signal reported movement away from a
  version nothing installs. That is why #17 sat open describing a pin two
  releases old. just pins now asserts the sites agree with each other,
  with no network, before anything asks upstream. Reported in #46 and #17.

• apply --verify is a real switch. It was a bool with
  default_value_t = true, which clap gives a SetTrue action — so
  --verify set what was already set, --no-verify was an unknown
  argument, and the help read as an opt-in for something mandatory. There
  is a --no-verify now, and the help says verification is on. This is
  what makes apply usable on a machine that has the run directory but not
  the analyzer and the pinned toolchain. Reported in #36.

• prune's verdict line says what it checked. The gate answers
  convergence and static shared-memory capacity at a --cc; it has no view
  of instruction availability, so a crate using an sm_80+ intrinsic under
  needs_cc = "7.5" prunes to 12 clean at --cc 7.5 and fails only when
  something finally lowers it for that part. needs_cc is the author's
  claim and is taken on trust — defensible, and nowhere stated, so "clean"
  read as "this kernel is fine at cc 7.5". docs/LIMITATIONS.md carries the
  long form, including why the two stronger fixes were not built. Reported
  in #32.

Fixed

• A kernel crate with a bin target no longer hard-stops the gate.
  reconverge prints one findings.v1 document per analyzed target — its
  documented contract — and this reader handed the whole of stdout to a
  single from_str, so a src/main.rs beside a kernel library, the
  ordinary shape of a GPU crate, made every candidate a tool error at
  trailing characters at line 2 column 1. In the Action fail-on
  defaults to tool-error, so CI went red for a crate with nothing wrong
  with it, pointing at the analyzer's tracker. Stdout is read as JSONL and
  the findings are unioned: a deny finding in any target refuses, and the
  bin target's document is harmless to merge. The fail-safe always held —
  it held against a format the analyzer documents. Reported in #42.

• The scratch copy is the whole crate. It took only the entries of
  src/ that are files, so mod util; with src/util/mod.rs — how Rust
  code is organised past one file — produced a scratch crate that could not
  compile, and the gate reported error: could not compile against a crate
  whose own cargo check is clean. The message told its author to fix
  build errors they do not have, or to reinstall their toolchain, and never
  said that what it compiled was not their crate. It copies recursively
  now, carries build.rs or whatever package.build names, skips
  target/, and a tool error names the scratch directory. Reported in #43.

• rustc's diagnostics survive the tool-error filter. #19 replaced a
  tail-six heuristic with a filter on marked lines, and picked the
  secondary marker: rustc's primary diagnostics begin error[E0583]:,
  a code before the colon. So what survived was cargo's summary and
  reconverge's generic hint — "see the errors above", with the one that was
  above removed. Both forms are accepted now, here and in the compile
  executor, which still had the tail heuristic #19 removed next door.
  Reported in #44.

• --budget cannot be given a value that fails to bound anything.
  split_at(text.len() - 1) on a trimmed-empty argument is 0usize - 1,
  so --budget "" panicked at exit 101. Worse: NaN and 1e400 parsed,
  and the guard is elapsed >= budget — false for every value against NaN,
  never true against infinity — so a value that looked accepted produced an
  unbounded measured sweep on real silicon, which is the one failure a
  budget exists to prevent. Non-finite and negative values are rejected,
  the message names the flag and the accepted forms, and min/hr are
  accepted alongside m/h because that is what people type. --budget 0
  stays valid and means what it always did. Reported in #33.

• apply decides about verification before it prints anything. It
  emitted the params.rs and then verified, so "refusing to emit"
  arrived after the emission and a reader who had piped stdout to a file
  had the file. On a Metal run it could never succeed at all: that path has
  no convergence gate, deliberately, so the run records gate_cc: "metal",
  and handing that sentinel to reconverge produced the correct answer to
  the wrong question ("metal is not a compute capability") dressed as a
  regression ("no longer passes the gate"). Nothing regressed; the gate
  never ran and cannot. It refuses by name now, before stdout, and points
  at --no-verify or prune --cc <target>. Verdict has a Display, so
  no user-facing message is a Rust struct literal. Reported in #34.

• A results.json the report cannot read is an error, not "unmeasured".
  A truncated file, an empty one, null, [], a results.v2 from a newer
  runner and a directory named results.json all rendered as "nothing
  measured yet": exit 0, nothing on stderr, and a JSON report that
  validated against the schema. The run directory is the hand-off between
  two machines and those two conditions call for opposite actions — wait,
  or go and look. Only NotFound is Ok(None) now; everything else names
  the path and the cause, the way verdicts.v1 already did fifteen lines
  away in the same function. model --results names the cause too, and
  tune's end-of-run report inherits all of it. Reported in #45.

• Nothing is cut mid-value or mid-word at the panel border. #24 fixed
  this on the chosen line and left it in the two views below: the ranking
  lost every closing bracket at eighty columns, so each interval read as a
  number with no upper bound, and the rejections view — the one the README
  calls the point of the tool — lost the clause that says what to do,
  stopping at splits a 64-threa and never reaching safe only at one warp (<= 32 threads). An interval is a field and is dropped whole through the
  same helper the chosen line uses; a reason is a sentence and wraps. A
  scan over every golden now fails on a value or a word ending at the
  border without an ellipsis — confirmed red against the shipped pre-fix
  frames, and it would have caught #24. Reported in #35.

• A missing cargo oxide is diagnosed by name. cargo's own help
  relayed cargo search cargo-oxide, and cargo-oxide is not on crates.io:
  cuda-oxide is a pinned git checkout. The one actionable-looking line sent
  the reader to a package that does not exist, on the first wall of stage
  and tune --backend cuda. The message now names the pin, gives the three
  commands CI uses, and says that prune needs none of it. The pin is a
  constant just pins checks, so a bump moves the message with it. In the
  same path, exit Some(101) is an exit code again and the compile failure
  reports the compiler's errors rather than its summary. Reported in #37.

• No flag on tune is accepted and silently ignored. --budget,
  --order and --seed are inert with --backend model, and --seed is
  inert with --order exhaustive on any backend. Each says so once, the
  way --out has since #22 — somebody who passes --budget 30m reasonably
  believes something is bounded. Reported in #38.

Install

$ cargo install launchbound-cli

In CI, the action is three lines and follows 2.x on its own:

- uses: actions/checkout@v7
- uses: vyncint/launchbound/action@v2
  with:
    cc: "8.6"

The gate installs cargo-reconverge 0.5.0 from crates.io on every run — a
cached analyzer is not evidence about what is published today.