Vercel dev spams console with TS Errors from node_modules .d.ts files

When running vercel dev locally, the terminal gets flooded with TypeScript errors coming from .d.ts files inside node_modules whenever a request is made. These errors are irrelevant to the project and makes the console output hard to read. Looking for a way to suppress or disable them during development.

Its a basic Hono app using vercel template.

SCR-20250829-dfaj

Vercel Staff

Do you have skipLibCheck: true in your tsconfig file? That's the relevant config for skipping node_modules and d.ts files

Having the same issue (Google brought me here). Seeing this with indeed skipLibCheck: true in my TSConfig.

tsconfig.json (root of project)

{
  "extends": "./tsconfig.base.json",
  "compilerOptions": {
    "target": "es2022",
    "module": "nodenext",
    "moduleResolution": "nodenext",
    "skipLibCheck": true,
    "isolatedModules": true,
    "noUnusedLocals": true,
    "noUnusedParameters": true,
    "noFallthroughCasesInSwitch": true,
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "resolveJsonModule": true,
    "types": ["node"]
  },
  "include": ["api"]
}

tsconfig.base.json

{
  "compilerOptions": {
    "noEmit": true,
    "noImplicitAny": true,
    "strict": true,
    "strictNullChecks": true,
    "isolatedModules": true,
    "skipLibCheck": true
  }
}

Also getting lots of them on the zod library, so should be pretty easy to reproduce just installing this.

reply to #3

Yes tsconfig had skipLibCheck set to true. I didn't change anything from the base hono/vercel template. I had installed zod and after importing that in any module it started giving typescript errors. Though the app runs, its constantly spamming console whenever the functions run.

Did you have any chance to have a look at this? This is kind of frustrating, since it basically buries all server-side logs or errors during development. I have updated the vercel package to 48.0.0, error is still persistent with the above tsconfigs.

Hey Tim, Can I ask what are you using it for? Because I was developing an api server using Hono and after this annoying bug I forced myself to switch to cloudflare with Hono, and its working like breeze. I don't know what is the issue with vercel cli locally though.

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{ "extends": "./tsconfig.base.json", "compilerOptions": { "target": "es2022", "module": "nodenext", "moduleResolution": "nodenext", "skipLibCheck": true, "isolatedModules": true, "noUnusedLocals": true, "noUnusedParameters": true, "noFallthroughCasesInSwitch": true, "esModuleInterop": true, "allowSyntheticDefaultImports": true, "resolveJsonModule": true, "types": ["node"] }, "include": ["api"] }