fix: point pn to pnpm binary directly, not to @pnpm/exe/pn

pnpm self-update only replaces the pnpm binary — it does not update
other files in the @pnpm/exe package (setup.js, pn, pnpx, pnx all
remain from the v10 bootstrap). So @pnpm/exe/pn may not exist at all.

Instead of relying on @pnpm/exe/pn, create the aliases directly:
- pn → symlink to the pnpm binary
- pnpx/pnx → shell scripts that exec "pnpm dlx"

Also remove the setup.js call after self-update since it's no longer
needed and would run the v10 version which doesn't know about pn.

src/install-pnpm/ensureAliasLinks.test.ts

@@ -12,16 +12,14 @@ async function createTempDir (): Promise<string> {
 async function setupStandaloneFixture (binDir: string): Promise<void> {
   const exeDir = path.join(binDir, '..', '@pnpm', 'exe')
   await mkdir(exeDir, { recursive: true })
-  await writeFile(path.join(exeDir, 'pn'), '#!/bin/sh\necho pn\n', { mode: 0o755 })
-  await writeFile(path.join(exeDir, 'pnpx'), '#!/bin/sh\necho pnpx\n', { mode: 0o755 })
-  await writeFile(path.join(exeDir, 'pnx'), '#!/bin/sh\necho pnx\n', { mode: 0o755 })
+  // Only the pnpm binary exists — pn/pnpx/pnx may not exist after self-update
+  await writeFile(path.join(exeDir, 'pnpm'), '#!/bin/sh\necho pnpm\n', { mode: 0o755 })
 }
 
 async function setupNonStandaloneFixture (binDir: string): Promise<void> {
   const pnpmBinDir = path.join(binDir, '..', 'pnpm', 'bin')
   await mkdir(pnpmBinDir, { recursive: true })
   await writeFile(path.join(pnpmBinDir, 'pnpm.cjs'), 'console.log("pnpm")\n')
-  await writeFile(path.join(pnpmBinDir, 'pnpx.cjs'), 'console.log("pnpx")\n')
 }
 
 describe('ensureAliasLinks', () => {
@@ -34,78 +32,85 @@ describe('ensureAliasLinks', () => {
   })
 
   describe('standalone mode', () => {
-    it('creates symlinks on unix when targets exist', async () => {
+    it('creates pn as symlink to pnpm binary on unix', async () => {
       await setupStandaloneFixture(binDir)
 
       await ensureAliasLinks(binDir, true, 'linux')
 
-      expect(existsSync(path.join(binDir, 'pn'))).toBe(true)
-      expect(existsSync(path.join(binDir, 'pnpx'))).toBe(true)
-      expect(existsSync(path.join(binDir, 'pnx'))).toBe(true)
-
       const pnTarget = await readlink(path.join(binDir, 'pn'))
-      expect(pnTarget).toBe(path.join('..', '@pnpm', 'exe', 'pn'))
+      expect(pnTarget).toBe(path.join('..', '@pnpm', 'exe', 'pnpm'))
     })
 
-    it('creates .cmd and .ps1 shims on windows when targets exist', async () => {
+    it('creates pnpx and pnx as shell scripts calling pnpm dlx on unix', async () => {
+      await setupStandaloneFixture(binDir)
+
+      await ensureAliasLinks(binDir, true, 'linux')
+
+      for (const name of ['pnpx', 'pnx']) {
+        const content = await readFile(path.join(binDir, name), 'utf8')
+        expect(content).toContain('pnpm')
+        expect(content).toContain('dlx')
+        expect(content).toContain('exec')
+      }
+    })
+
+    it('creates .cmd and .ps1 shims on windows', async () => {
       await setupStandaloneFixture(binDir)
 
       await ensureAliasLinks(binDir, true, 'win32')
 
-      // Should create .cmd shims, not extensionless symlinks
-      expect(existsSync(path.join(binDir, 'pn.cmd'))).toBe(true)
-      expect(existsSync(path.join(binDir, 'pnx.cmd'))).toBe(true)
-      expect(existsSync(path.join(binDir, 'pn.ps1'))).toBe(true)
-      expect(existsSync(path.join(binDir, 'pnx.ps1'))).toBe(true)
+      // pn shims
+      const pnCmd = await readFile(path.join(binDir, 'pn.cmd'), 'utf8')
+      expect(pnCmd).toContain('pnpm')
+      expect(pnCmd).toContain('%*')
+      expect(pnCmd).not.toContain('dlx')
 
-      // Should not create extensionless symlinks on windows
+      const pnPs1 = await readFile(path.join(binDir, 'pn.ps1'), 'utf8')
+      expect(pnPs1).toContain('pnpm')
+      expect(pnPs1).toContain('@args')
+
+      // pnpx/pnx shims call pnpm dlx
+      const pnpxCmd = await readFile(path.join(binDir, 'pnpx.cmd'), 'utf8')
+      expect(pnpxCmd).toContain('pnpm')
+      expect(pnpxCmd).toContain('dlx')
+
+      // Should not create extensionless files on windows
       expect(existsSync(path.join(binDir, 'pn'))).toBe(false)
-      expect(existsSync(path.join(binDir, 'pnx'))).toBe(false)
-
-      const cmdContent = await readFile(path.join(binDir, 'pn.cmd'), 'utf8')
-      expect(cmdContent).toContain(path.join('..', '@pnpm', 'exe', 'pn'))
-      expect(cmdContent).toContain('%*')
-
-      const ps1Content = await readFile(path.join(binDir, 'pn.ps1'), 'utf8')
-      expect(ps1Content).toContain(path.join('..', '@pnpm', 'exe', 'pn'))
-      expect(ps1Content).toContain('@args')
     })
   })
 
   describe('non-standalone mode', () => {
-    it('creates symlinks on unix when targets exist', async () => {
+    it('creates pn as symlink to pnpm.cjs on unix', async () => {
       await setupNonStandaloneFixture(binDir)
 
       await ensureAliasLinks(binDir, false, 'linux')
 
-      expect(existsSync(path.join(binDir, 'pn'))).toBe(true)
-      expect(existsSync(path.join(binDir, 'pnpx'))).toBe(true)
-      expect(existsSync(path.join(binDir, 'pnx'))).toBe(true)
-
       const pnTarget = await readlink(path.join(binDir, 'pn'))
       expect(pnTarget).toBe(path.join('..', 'pnpm', 'bin', 'pnpm.cjs'))
-
-      // pnx should point to pnpx.cjs (same as pnpx)
-      const pnxTarget = await readlink(path.join(binDir, 'pnx'))
-      expect(pnxTarget).toBe(path.join('..', 'pnpm', 'bin', 'pnpx.cjs'))
     })
 
-    it('creates .cmd shims on windows when targets exist', async () => {
+    it('creates pnpx/pnx scripts on unix', async () => {
+      await setupNonStandaloneFixture(binDir)
+
+      await ensureAliasLinks(binDir, false, 'linux')
+
+      const content = await readFile(path.join(binDir, 'pnpx'), 'utf8')
+      expect(content).toContain('pnpm.cjs')
+      expect(content).toContain('dlx')
+    })
+
+    it('creates .cmd shims on windows', async () => {
       await setupNonStandaloneFixture(binDir)
 
       await ensureAliasLinks(binDir, false, 'win32')
 
-      expect(existsSync(path.join(binDir, 'pn.cmd'))).toBe(true)
-
       const cmdContent = await readFile(path.join(binDir, 'pn.cmd'), 'utf8')
-      expect(cmdContent).toContain(path.join('..', 'pnpm', 'bin', 'pnpm.cjs'))
+      expect(cmdContent).toContain(path.join('pnpm', 'bin', 'pnpm.cjs'))
     })
   })
 
-  describe('skips when targets do not exist', () => {
-    it('creates no links when target directory is empty (v10)', async () => {
-      // Don't create any fixture files — simulates pnpm v10 without aliases
-
+  describe('skips when pnpm binary does not exist', () => {
+    it('creates no links on unix', async () => {
       await ensureAliasLinks(binDir, true, 'linux')
 
       expect(existsSync(path.join(binDir, 'pn'))).toBe(false)
@@ -113,25 +118,23 @@ describe('ensureAliasLinks', () => {
       expect(existsSync(path.join(binDir, 'pnx'))).toBe(false)
     })
 
-    it('creates no shims on windows when targets do not exist', async () => {
+    it('creates no shims on windows', async () => {
       await ensureAliasLinks(binDir, true, 'win32')
 
       expect(existsSync(path.join(binDir, 'pn.cmd'))).toBe(false)
-      expect(existsSync(path.join(binDir, 'pnx.cmd'))).toBe(false)
     })
   })
 
-  describe('overwrites existing broken links', () => {
-    it('replaces existing file with symlink on unix', async () => {
+  describe('overwrites existing broken shims', () => {
+    it('replaces npm broken shim with symlink on unix', async () => {
       await setupStandaloneFixture(binDir)
-      // Simulate npm's broken shim (points to .tools/ placeholder)
-      await writeFile(path.join(binDir, 'pn'), '#!/bin/sh\nexec broken\n')
+      // Simulate npm's broken shim pointing to .tools/ placeholder
+      await writeFile(path.join(binDir, 'pn'), '#!/bin/sh\nexec .tools/broken "$@"\n')
 
       await ensureAliasLinks(binDir, true, 'linux')
 
-      // Should be replaced with a symlink to the real target
       const target = await readlink(path.join(binDir, 'pn'))
-      expect(target).toBe(path.join('..', '@pnpm', 'exe', 'pn'))
+      expect(target).toBe(path.join('..', '@pnpm', 'exe', 'pnpm'))
     })
 
     it('replaces existing .cmd shims on windows', async () => {
@@ -141,7 +144,7 @@ describe('ensureAliasLinks', () => {
       await ensureAliasLinks(binDir, true, 'win32')
 
       const content = await readFile(path.join(binDir, 'pn.cmd'), 'utf8')
-      expect(content).toContain(path.join('..', '@pnpm', 'exe', 'pn'))
+      expect(content).toContain('pnpm')
     })
   })
 })

src/install-pnpm/ensureAliasLinks.ts

@@ -2,32 +2,16 @@ import { unlink, writeFile, symlink } from 'fs/promises'
 import { existsSync } from 'fs'
 import path from 'path'
 
-interface AliasDefinition {
-  name: string
-  target: string
+function shScript (command: string): string {
+  return `#!/bin/sh\nexec ${command} "$@"\n`
 }
 
-function getAliases (standalone: boolean): AliasDefinition[] {
-  if (standalone) {
-    return [
-      { name: 'pn', target: path.join('..', '@pnpm', 'exe', 'pn') },
-      { name: 'pnpx', target: path.join('..', '@pnpm', 'exe', 'pnpx') },
-      { name: 'pnx', target: path.join('..', '@pnpm', 'exe', 'pnx') },
-    ]
-  }
-  return [
-    { name: 'pn', target: path.join('..', 'pnpm', 'bin', 'pnpm.cjs') },
-    { name: 'pnpx', target: path.join('..', 'pnpm', 'bin', 'pnpx.cjs') },
-    { name: 'pnx', target: path.join('..', 'pnpm', 'bin', 'pnpx.cjs') },
-  ]
+function cmdShim (command: string): string {
+  return `@ECHO off\r\n${command} %*\r\n`
 }
 
-function cmdShim (target: string): string {
-  return `@ECHO off\r\n"%~dp0\\${target}" %*\r\n`
-}
-
-function pwshShim (target: string): string {
-  return `#!/usr/bin/env pwsh\n& "$PSScriptRoot\\${target}" @args\n`
+function pwshShim (command: string): string {
+  return `#!/usr/bin/env pwsh\n${command} @args\n`
 }
 
 async function forceSymlink (target: string, linkPath: string): Promise<void> {
@@ -35,27 +19,52 @@ async function forceSymlink (target: string, linkPath: string): Promise<void> {
   await symlink(target, linkPath)
 }
 
+async function forceWriteFile (filePath: string, content: string, mode?: number): Promise<void> {
+  try { await unlink(filePath) } catch {}
+  await writeFile(filePath, content, { mode })
+}
+
 /**
  * Create pn/pnpx/pnx alias links in the bin directory.
- * On Unix, creates symlinks. On Windows, creates .cmd and .ps1 shims.
- * Only creates links when the target file actually exists (pnpm v11+).
  *
- * Existing links are always replaced because npm may have created shims
- * pointing to an isolated .tools/ copy that has stale placeholder files.
+ * pn is an alias for pnpm, so it symlinks (or shims) to the pnpm binary.
+ * pnpx/pnx are aliases for "pnpm dlx", created as shell scripts.
+ *
+ * This does NOT rely on the @pnpm/exe package having pn/pnx files, because
+ * pnpm self-update only replaces the pnpm binary — it doesn't update other
+ * files in the package. The aliases are created by pointing pn directly to
+ * the pnpm binary, and pnpx/pnx as scripts that exec "pnpm dlx".
+ *
+ * Only creates links when the pnpm binary exists in the expected location
+ * (i.e. the package has been installed). This is always true after bootstrap.
  */
 export async function ensureAliasLinks (binDir: string, standalone: boolean, platform: NodeJS.Platform = process.platform): Promise<void> {
-  const aliases = getAliases(standalone)
   const isWindows = platform === 'win32'
 
-  for (const { name, target } of aliases) {
-    const resolvedTarget = path.resolve(binDir, target)
-    if (!existsSync(resolvedTarget)) continue
+  // Determine the pnpm binary path relative to binDir
+  const pnpmTarget = standalone
+    ? path.join('..', '@pnpm', 'exe', 'pnpm')
+    : path.join('..', 'pnpm', 'bin', 'pnpm.cjs')
 
-    if (isWindows) {
-      await writeFile(path.join(binDir, `${name}.cmd`), cmdShim(target))
-      await writeFile(path.join(binDir, `${name}.ps1`), pwshShim(target))
-    } else {
-      await forceSymlink(target, path.join(binDir, name))
+  const resolvedPnpm = path.resolve(binDir, pnpmTarget)
+  if (!existsSync(resolvedPnpm)) return
+
+  if (isWindows) {
+    // pn → calls pnpm directly
+    await writeFile(path.join(binDir, 'pn.cmd'), cmdShim(`"%~dp0\\${pnpmTarget}"`))
+    await writeFile(path.join(binDir, 'pn.ps1'), pwshShim(`& "$PSScriptRoot\\${pnpmTarget}"`))
+    // pnpx/pnx → calls pnpm dlx
+    for (const name of ['pnpx', 'pnx']) {
+      await writeFile(path.join(binDir, `${name}.cmd`), cmdShim(`"%~dp0\\${pnpmTarget}" dlx`))
+      await writeFile(path.join(binDir, `${name}.ps1`), pwshShim(`& "$PSScriptRoot\\${pnpmTarget}" dlx`))
+    }
+  } else {
+    // pn → symlink to pnpm binary
+    await forceSymlink(pnpmTarget, path.join(binDir, 'pn'))
+    // pnpx/pnx → shell scripts that exec pnpm dlx
+    for (const name of ['pnpx', 'pnx']) {
+      const pnpmPath = `"$(dirname "$0")/${pnpmTarget}"`
+      await forceWriteFile(path.join(binDir, name), shScript(`${pnpmPath} dlx`), 0o755)
     }
   }
 }

src/install-pnpm/run.ts

@@ -59,17 +59,6 @@ export async function runSelfInstaller(inputs: Inputs): Promise<number> {
     if (exitCode !== 0) {
       return exitCode
     }
-
-    // self-update replaces package files but does not re-run preinstall
-    // scripts, so setup.js (which hardlinks pn/pnpx/pnx to the binary)
-    // needs to be run explicitly.
-    if (standalone) {
-      const exeDir = path.join(dest, 'node_modules', '@pnpm', 'exe')
-      const setupScript = path.join(exeDir, 'setup.js')
-      if (existsSync(setupScript)) {
-        await runCommand(process.execPath, [setupScript], { cwd: exeDir })
-      }
-    }
   }
 
   // Create pn/pnx alias bin links if the installed version supports them