ci: deprecate the repository and stop the scheduled measurement

.github/workflows/measure-random-missing.yml

@@ -1,8 +1,8 @@
 name: Measure random missing data point
 
+# Ran every 30 minutes until the fixtures stopped building; see README.md.
+# Kept dispatch-only so a data point can still be filled in by hand.
 on:
-  schedule:
-    - cron: "*/30 * * * *"
   workflow_dispatch:
 jobs:
   bench:

.github/workflows/verify-stability.yml

@@ -1,9 +1,8 @@
 name: Verify Stability
 
+# Dispatch-only since the repository was deprecated; a push to main would
+# otherwise start a benchmark run nobody reads. See README.md.
 on:
-  push:
-    branches:
-      - main
   workflow_dispatch:
 
 jobs:

README.md

@@ -0,0 +1,66 @@
+# webpack/benchmark
+
+> [!IMPORTANT]
+> **This repository is deprecated.** Performance measurement for webpack now
+> lives in [webpack/webpack](https://github.com/webpack/webpack). Nothing here
+> runs on a schedule any more, and the results are a frozen archive.
+
+Long-horizon build measurements for webpack: real applications, installed with
+their dependencies as of a given date, built with the webpack of that same date.
+The historical results are plotted at <https://webpack.github.io/benchmark/>.
+
+## Where measurement happens now
+
+`.github/workflows/benchmarks.yml` in webpack/webpack runs the cases in
+`test/benchmarkCases/` through [CodSpeed](https://codspeed.io/webpack/webpack)
+on every pull request and every push to `main`, in both simulation and memory
+mode. That is where a regression is caught and where the trend is tracked; this
+repository never gated anything.
+
+Of the 21 addon scenarios this repository carried, webpack/webpack already
+covered eight (both source-map variants, `future-defaults`, `persistent-cache`,
+and the CPU and heap profiles through its own runner modes). Ten more were
+ported into `test/benchmarkCases/` there: a loader in the pipeline, a cold
+persistent cache and HMR in webpack/webpack#21858, then `no-minimize`,
+`no-concatenation`, `no-exports-analysis`, the three unsafe-cache variants and a
+modern `common-libs` in webpack/webpack#21864.
+
+Five are deliberately not ported, and stay recorded here rather than being lost
+quietly:
+
+| Scenario                                      | Why                                                                                                                                          |
+| --------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------- |
+| `swc-env`, `swc-env-minimize`, `swc-minimize` | need `@swc/core` / `swc-loader` / `terser-webpack-plugin`, which webpack does not depend on                                                  |
+| `thread-babel-env`                            | needs `thread-loader`                                                                                                                        |
+| babel `preset-env`                            | needs `@babel/preset-env`; the ported `loader-babel` uses `preset-react`                                                                     |
+| `pnp`                                         | needs a Yarn PnP install layout the in-repo harness cannot produce                                                                           |
+| `no-cache`                                    | inexpressible there — the watch scenario overrides `cache`, and each iteration builds a fresh compiler, so a memory cache never carries over |
+
+The `cases/` fixtures are not ported. `rome` is an archived project whose case no
+longer builds, `atlaskit-editor` pins React 16 with `@atlaskit/editor-core` 120,
+and the old `common-libs` pinned Material-UI 4, Vue 2, moment and jQuery; the
+replacement uses the modern libraries webpack already depends on.
+
+## What is kept, and why
+
+The `gh-pages` branch holds ~77k measurements of webpack releases going back to
+2020, each against the npm ecosystem as it stood at the time. CodSpeed cannot
+reconstruct that: it knows only the commits it has measured since it was
+enabled, and it does not build real applications. **That archive stays as it
+is** — please do not rewrite or delete the branch.
+
+## Why the schedule was switched off
+
+A cron measured a random missing data point every 30 minutes, for over 16,000
+runs. Roughly two in five ended in a build failure: the cases pin
+`dependenciesDate` for their `dependencies` but leave dev dependencies floating,
+so `rome` resolves `typescript` and `ts-loader` to a compiler that rejects the
+case's own `tsconfig.json` (`TS5107: Option 'moduleResolution=node10' is
+deprecated`). The newest data point ended up older than the historic ones the
+cron kept backfilling.
+
+## Running something by hand
+
+Every workflow is still available through **Run workflow** in the Actions tab —
+`compare.yml` takes two versions or dates. Reviving any schedule means pinning
+each case's dev dependencies first.