fix: ensure PNPM_HOME/bin is in PATH during pnpm setup

When upgrading from old pnpm (global bin = PNPM_HOME) to new pnpm
(global bin = PNPM_HOME/bin), `pnpm setup` would fail because the
spawned `pnpm add -g` checks that the global bin dir is in PATH.
Prepend PNPM_HOME/bin to PATH in the spawned process env so the
check passes during the transition.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

engine/pm/commands/package.json

@@ -50,6 +50,7 @@
     "@pnpm/store.controller": "workspace:*",
     "@pnpm/types": "workspace:*",
     "@pnpm/workspace.project-manifest-reader": "workspace:*",
+    "path-name": "catalog:",
     "ramda": "catalog:",
     "render-help": "catalog:",
     "semver": "catalog:",

engine/pm/commands/src/setup/setup.ts

@@ -10,6 +10,7 @@ import {
   type ConfigReport,
   type PathExtenderReport,
 } from '@pnpm/os.env.path-extender'
+import PATH from 'path-name'
 import { renderHelp } from 'render-help'
 
 export const rcOptionsTypes = (): Record<string, unknown> => ({})
@@ -80,11 +81,13 @@ function installCliGlobally (execPath: string, pnpmHomeDir: string): void {
   })
 
   try {
+    const binDir = path.join(pnpmHomeDir, 'bin')
     const { status, error } = spawnSync(execPath, ['add', '-g', `file:${execDir}`], {
       stdio: 'inherit',
       env: {
         ...process.env,
         PNPM_HOME: pnpmHomeDir,
+        [PATH]: `${binDir}${path.delimiter}${process.env[PATH] ?? ''}`,
       },
     })
 

pnpm-lock.yaml

@@ -3524,6 +3524,9 @@ importers:
       '@pnpm/workspace.project-manifest-reader':
         specifier: workspace:*
         version: link:../../../workspace/project-manifest-reader
+      path-name:
+        specifier: 'catalog:'
+        version: 1.0.0
       ramda:
         specifier: 'catalog:'
         version: '@pnpm/ramda@0.28.1'