fix: survive the re-warm on every manager, and drop Yarn PnP

.gitignore

@@ -9,3 +9,4 @@ managers
 versions.json
 
 samples
+.claude

benchmarkFixture.js

@@ -203,9 +203,10 @@ export function pnpmWorkspaceYaml (opts = {}) {
 }
 
 /**
- * Undoes an install. Yarn PnP writes no `node_modules` at all, so removing only
- * that would leave its whole installation in place and hand the scenario that
- * follows a project that is already installed.
+ * Undoes an install. Yarn Berry can write installation state outside
+ * `node_modules` (the PnP artifacts, its own metadata), so removing only
+ * `node_modules` would hand the scenario that follows a project that is
+ * partly installed already.
  */
 function removeInstallOutput (cwd, modules) {
   if (modules) {
@@ -269,9 +270,6 @@ export default async function benchmark (pm, fixture, opts) {
                 + 'nmMode: hardlinks-local\n'
                 + 'compressionLevel: 0\n'
         break
-      case 'yarn_pnp':
-        yarnRc += 'nodeLinker: pnp\n'
-        break
     }
     await fs.writeFile(path.join(cwd, '.yarnrc.yml'), yarnRc)
   }
@@ -390,7 +388,12 @@ export default async function benchmark (pm, fixture, opts) {
   // lockfile and no `node_modules` go with it, or the fast managers would
   // short-circuit and warm nothing, which is how the imbalance arose in the
   // first place.
-  const rewarmDir = path.join(cwd, '.rewarm')
+  // A sibling of the project, not a directory inside it: Yarn walks up from
+  // wherever it runs and refuses to install in a directory nested under a
+  // project that doesn't declare it ("doesn't seem to be part of the project
+  // declared in ..."), so the throwaway copy has to live where no project
+  // sits above it.
+  const rewarmDir = path.join(path.dirname(cwd), `${path.basename(cwd)}.rewarm`)
   rimraf.sync(rewarmDir)
   await fs.mkdir(rewarmDir, { recursive: true })
   try {
@@ -406,6 +409,10 @@ export default async function benchmark (pm, fixture, opts) {
         if (err?.code !== 'ENOENT') throw err
       }
     }
+    // For Yarn this drops an empty lockfile in place, the same project-root
+    // marker every scenario below relies on (see `cleanLockfile`); for the
+    // others it is a no-op on a directory that has no lockfile to remove.
+    cleanLockfile(pm, rewarmDir, env)
     // The cache dir may not exist right now: it was deleted two rows up, and
     // a manager whose `node_modules` row is a registry-free no-op (pnpm
     // restores the tree from the lockfile copy inside it) never recreated

commandsMap.js

@@ -74,15 +74,6 @@ export default {
       'install'
     ]
   },
-  yarn_pnp: {
-    scenario: 'yarn_pnp',
-    legend: 'Yarn PnP',
-    color: '#40a9ff',
-    name: 'yarn',
-    args: [
-      'install'
-    ]
-  },
   bun: {
     scenario: 'bun',
     legend: 'Bun',

index.js

@@ -68,7 +68,6 @@ const pmConfigs = [
   // between the two.
   { key: 'pnpm_pnpr' },
   { key: 'yarn' },
-  { key: 'yarn_pnp', hasNodeModules: false },
   { key: 'bun' },
 ]
 const pms = pmConfigs.map(({ key }) => key)
@@ -305,7 +304,6 @@ async function measure () {
       authToken: registry.authToken,
     },
     yarn: { managersDir: managersDirs.yarn },
-    yarn_pnp: { managersDir: managersDirs.yarn },
     bun: { managersDir: managersDirs.bun },
   }
   // A column with nowhere to install from would otherwise fail eight minutes
@@ -375,7 +373,7 @@ async function writePage ({ formattedNow, registryVersion, sections, svgs, sorte
 
   **Last benchmarked at**: _${formattedNow}_ (_daily_ updated).
 
-  This benchmark compares the performance of npm, pnpm, Yarn, Yarn PnP, and Bun (check [Yarn's benchmarks](https://yarnpkg.com/benchmarks) for any other Yarn modes that are not included here). Every package manager installs through the same [pnpr](https://pnpm.io/pnpr) registry (v${registryVersion}) across an emulated ${ROUND_TRIP_MS}ms round trip at ${BANDWIDTH_MBPS} Mbit/s, so they all face one registry over one reproducible network instead of whatever link the benchmark machine happens to have. pnpm 12 is measured twice: once on its own, and once resolving its dependency graph [on the server](https://pnpm.io/pnpr/install-acceleration) instead of walking it itself. The page also compares how fast pnpm, fnm, and nvm install and switch Node.js versions.
+  This benchmark compares the performance of npm, pnpm, Yarn, and Bun (check [Yarn's benchmarks](https://yarnpkg.com/benchmarks) for PnP and any other Yarn modes that are not included here). Every package manager installs through the same [pnpr](https://pnpm.io/pnpr) registry (v${registryVersion}) across an emulated ${ROUND_TRIP_MS}ms round trip at ${BANDWIDTH_MBPS} Mbit/s, so they all face one registry over one reproducible network instead of whatever link the benchmark machine happens to have. pnpm 12 is measured twice: once on its own, and once resolving its dependency graph [on the server](https://pnpm.io/pnpr/install-acceleration) instead of walking it itself. The page also compares how fast pnpm, fnm, and nvm install and switch Node.js versions.
 
   About the setup:
 
@@ -456,7 +454,6 @@ async function benchmarkFixtures ({ pmCommands, formattedNow, nodeVersion, runFi
         secondaryKey: 'pnpm11',
       },
       { ...pmCommands.yarn, key: 'yarn' },
-      { ...pmCommands.yarn_pnp, key: 'yarn_pnp' },
       { ...pmCommands.bun, key: 'bun' },
     ]
     const resArray = sortedTests.map(test => mainBars.map(bar => bar.stacked

regenerate-svgs.mjs

@@ -62,7 +62,6 @@ const pmConfigs = [
   { key: 'pnpm11' },
   { key: 'pnpm12' },
   { key: 'yarn' },
-  { key: 'yarn_pnp', hasNodeModules: false },
   { key: 'bun' },
 ]
 
@@ -142,7 +141,6 @@ const mainBars = [
     secondaryKey: 'pnpm11',
   },
   { ...cmdsMap.yarn, key: 'yarn' },
-  { ...cmdsMap.yarn_pnp, key: 'yarn_pnp' },
   { ...cmdsMap.bun, key: 'bun' },
 ]
   .filter(bar => bar.stacked