fix: don't remove the modules directory, just the contents of it

close #2720
PR #2722

.changeset/dirty-comics-doubt.md

@@ -0,0 +1,5 @@
+---
+"@pnpm/get-context": patch
+---
+
+When purging an incompatible modules directory, don't remove the actual directory, just the contents of it.

packages/get-context/src/index.ts

@@ -276,12 +276,22 @@ async function purgeModulesDirsOfImporter (
     prefix: importer.rootDir,
   })
   try {
-    await rimraf(importer.modulesDir)
+    // We don't remove the actual modules directory, just the contents of it.
+    // 1. we will need the directory anyway.
+    // 2. in some setups, pnpm won't even have permission to remove the modules directory.
+    await removeContentsOfDir(importer.modulesDir)
   } catch (err) {
     if (err.code !== 'ENOENT') throw err
   }
 }
 
+async function removeContentsOfDir (dir: string) {
+  const items = await fs.readdir(dir)
+  for (const item of items) {
+    await rimraf(path.join(dir, item))
+  }
+}
+
 function stringifyIncludedDeps (included: IncludedDependencies) {
   return DEPENDENCIES_FIELDS.filter((depsField) => included[depsField]).join(', ')
 }