fix(list): limit manifest reads for large workspaces (#11692)

.changeset/olive-spies-listen.md

@@ -0,0 +1,7 @@
+---
+"@pnpm/deps.inspection.list": patch
+"@pnpm/workspace.project-manifest-reader": patch
+"pnpm": patch
+---
+
+Limit concurrent project manifest reads while listing large workspaces to avoid `EMFILE` errors.

pnpm-lock.yaml

@@ -9638,6 +9638,9 @@ importers:
       json5:
         specifier: 'catalog:'
         version: 2.2.3
+      p-limit:
+        specifier: 'catalog:'
+        version: 7.3.0
       parse-json:
         specifier: 'catalog:'
         version: 8.3.0

workspace/project-manifest-reader/package.json

@@ -41,6 +41,7 @@
     "fast-deep-equal": "catalog:",
     "is-windows": "catalog:",
     "json5": "catalog:",
+    "p-limit": "catalog:",
     "parse-json": "catalog:",
     "read-yaml-file": "catalog:",
     "strip-bom": "catalog:"

workspace/project-manifest-reader/src/index.ts

@@ -9,6 +9,7 @@ import { writeProjectManifest } from '@pnpm/workspace.project-manifest-writer'
 import detectIndent from 'detect-indent'
 import equal from 'fast-deep-equal'
 import isWindows from 'is-windows'
+import pLimit from 'p-limit'
 import { readYamlFile } from 'read-yaml-file'
 
 import {
@@ -18,15 +19,19 @@ import {
 
 export type WriteProjectManifest = (manifest: ProjectManifest, force?: boolean) => Promise<void>
 
+const limitProjectManifestReads = pLimit(4)
+
 export async function safeReadProjectManifestOnly (projectDir: string): Promise<ProjectManifest | null> {
-  try {
-    return await readProjectManifestOnly(projectDir)
-  } catch (err: any) { // eslint-disable-line
-    if ((err as NodeJS.ErrnoException).code === 'ERR_PNPM_NO_IMPORTER_MANIFEST_FOUND') {
-      return null
+  return limitProjectManifestReads(async () => {
+    try {
+      return await readProjectManifestOnly(projectDir)
+    } catch (err: any) { // eslint-disable-line
+      if ((err as NodeJS.ErrnoException).code === 'ERR_PNPM_NO_IMPORTER_MANIFEST_FOUND') {
+        return null
+      }
+      throw err
     }
-    throw err
-  }
+  })
 }
 
 export async function readProjectManifest (projectDir: string): Promise<{