diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml index 08faeb5..e1c4016 100644 --- a/.github/workflows/ci.yml +++ b/.github/workflows/ci.yml @@ -200,6 +200,67 @@ jobs: # Total Upload: 58553.98 KiB # 1.96 KiB low — 0.0033%. The reading tracks the enforced figure. # + # ## Accurate against the limit; NOT repeatable to better than a few KiB + # + # #277. Accuracy is this gate's job and the figure above is the right + # claim for it. It says nothing about REPEATABILITY, and a reader who + # meets 0.0033% at the point of use will reasonably assume a small + # per-PR delta means something. Measured, it does not. + # + # The strongest control is ONE commit run twice, with no tree difference + # at all — not a workflow file, not a specifier line, nothing. `66cb0a4` + # is an empty commit whose tree hash is byte-identical to `main`'s at + # `50aacb9`; run 34252385192, attempts 1 and 2, landed on two different + # `ubuntu-latest` runners. The third reading is from `1bf8b70`, a + # DIFFERENT tree — it carries this comment — but the same bundle inputs, + # since a workflow file cannot enter the Worker. Bundle-identical, not + # tree-identical: the weaker of the two controls, and labelled as one. + # + # 66cb0a4 attempt 1, job 102149701548 58549.04 KiB + # 66cb0a4 attempt 2, job 102152795435 58553.46 KiB + # 1bf8b70 run 34277657373, job 102234545211 58549.06 KiB + # + # Largest gap: 4.42 KiB, between two runs of the SAME commit. That is + # larger than the 1.96 KiB agreement above, so the agreement cannot be + # read as sub-KiB precision either — it is one comparison, taken inside + # this much noise. + # + # The SHAPE is a tight cluster and one outlier, NOT a wander across a + # 4.42 KiB band: two of the three agree to 0.02 KiB and the third sits + # ~4.4 KiB above both. Three points cannot carry a distribution and none + # is modelled here. What is claimed is only that repeated readings over + # identical bundle inputs are not equal, and how far apart the measured + # ones landed. + # + # wrangler's gzip column moves too — 8800.26, 8800.65, 8797.64 KiB — so + # the artifact's bytes genuinely differ; this is not the same number + # being displayed differently. It does not track the raw figure (the + # third reading has the smallest compressed size and a middling raw + # one), so it confirms that much and nothing more. + # + # Holding the machine fixed shrinks the spread without closing it: four + # cold rebuilds of `66cb0a4`'s tree in one container gave 58548.93, + # 58548.93, 58548.94 and 58549.55 KiB — 0.62 KiB apart. + # + # So this number answers "is the bundle near the ceiling", not "did my + # PR grow the bundle". A single-digit-KiB move between two commits is + # inside the spread measured above and has not been shown to be a change + # in the bundle at all; a real growth of a few KiB is equally invisible. + # Attributing a small delta needs a same-tree control — the same commit + # run twice — not the previous commit's reading. + # + # n is small (3 CI runs, 4 local builds) and 4.42 KiB is the largest + # same-tree gap MEASURED, not a proven bound. Causes are NOT measured + # here and none is claimed. + # + # ⚠️ A SNAPSHOT at the commits named above, deliberately NOT maintained. + # Every run of this workflow produces another reading, so "fold in the + # latest" has no end; the population was frozen at these three instead + # of chased. Nobody is obliged to update this block, and a later reading + # that differs is the point being made, not a defect in it. If the + # question ever needs more than "a few KiB", take a fresh same-commit + # series rather than appending to this one. + # # ## The budget # # ONE constant, below, with the limit written beside it; every