fix(headless): don't create broken symlinks

close #2916
PR #3032

.changeset/hungry-dolls-rush.md

@@ -0,0 +1,5 @@
+---
+"@pnpm/headless": patch
+---
+
+Don't create broken symlinks to skipped optional dependencies, when hoisting.

packages/headless/src/index.ts

@@ -223,6 +223,11 @@ export default async (opts: HeadlessOptions) => {
       pnpmVersion: opts.currentEngine.pnpmVersion,
     } as LockfileToDepGraphOptions
   )
+  if (filteredLockfile.packages) {
+    for (const skippedDepPath of Array.from(skipped)) {
+      delete filteredLockfile.packages[skippedDepPath]
+    }
+  }
   if (opts.enablePnp) {
     const importerNames = R.fromPairs(
       opts.projects.map(({ manifest, id }) => [id, manifest.name ?? id])

packages/supi/test/install/hoist.ts

@@ -499,3 +499,27 @@ test('should recreate node_modules with hoisting', async () => {
     expect(Object.keys(modulesManifest?.hoistedDependencies ?? {}).length > 0).toBeTruthy()
   }
 })
+
+test('hoisting should not create a broken symlink to a skipped optional dependency', async () => {
+  const project = prepareEmpty()
+  console.log(process.cwd())
+
+  await install({
+    optionalDependencies: {
+      'not-compatible-with-any-os': '*',
+    },
+  }, await testDefaults({ publicHoistPattern: '*' }))
+
+  await project.hasNot('dep-of-optional-pkg')
+
+  // Verifying the same with headless installation
+  await rimraf('node_modules')
+
+  await install({
+    optionalDependencies: {
+      'not-compatible-with-any-os': '*',
+    },
+  }, await testDefaults({ publicHoistPattern: '*' }))
+
+  await project.hasNot('dep-of-optional-pkg')
+})