TypeError in Next.js

2025-06-214 turns11,665 charsgpt-4o

Summary

User encountered a deployment error in Next.js and requested a Cline prompt to fix it.

Messages

42:14 AM: build-image version: 235a96ed6c11cbdf942eed7e70e6802956f9b464 (focal)
42:14 AM: buildbot version: 5276eccdd060881dae1f6d00b54ef962dbbaa654
42:14 AM: Fetching cached dependencies
42:14 AM: Starting to download cache of 407.6MB (Last modified: 2025-06-21 15:40:43 +0000 UTC)
42:16 AM: Finished downloading cache in 1.947s
42:16 AM: Starting to extract cache
42:19 AM: Finished extracting cache in 2.984s
42:19 AM: Finished fetching cache in 5.008s
42:19 AM: Starting to prepare the repo for build
42:19 AM: Preparing Git Reference refs/heads/master
42:21 AM: Starting to install dependencies
42:21 AM: Started restoring cached mise cache
42:22 AM: Finished restoring cached mise cache
42:23 AM: mise python@3.13.5   install
42:23 AM: mise python@3.13.5   download cpython-3.13.5+20250612-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz
42:23 AM: mise python@3.13.5   extract cpython-3.13.5+20250612-x86_64-unknown-linux-gnu-install_only_stripped.tar.gz
42:24 AM: mise python@3.13.5   python --version
42:24 AM: mise python@3.13.5   Python 3.13.5
42:24 AM: mise python@3.13.5 ✓ installed
42:24 AM: Python version set to 3.13
42:25 AM: Collecting pipenv
42:25 AM:   Downloading pipenv-2025.0.3-py3-none-any.whl.metadata (17 kB)
42:25 AM: Collecting certifi (from pipenv)
42:25 AM:   Downloading certifi-2025.6.15-py3-none-any.whl.metadata (2.4 kB)
42:25 AM: Collecting packaging>=22 (from pipenv)
42:25 AM:   Downloading packaging-25.0-py3-none-any.whl.metadata (3.3 kB)
42:25 AM: Collecting setuptools>=67 (from pipenv)
42:25 AM:   Downloading setuptools-80.9.0-py3-none-any.whl.metadata (6.6 kB)
42:25 AM: Collecting virtualenv>=20.24.2 (from pipenv)
42:25 AM:   Downloading virtualenv-20.31.2-py3-none-any.whl.metadata (4.5 kB)
42:25 AM: Collecting distlib<1,>=0.3.7 (from virtualenv>=20.24.2->pipenv)
42:25 AM:   Downloading distlib-0.3.9-py2.py3-none-any.whl.metadata (5.2 kB)
42:25 AM: Collecting filelock<4,>=3.12.2 (from virtualenv>=20.24.2->pipenv)
42:25 AM:   Downloading filelock-3.18.0-py3-none-any.whl.metadata (2.9 kB)
42:25 AM: Collecting platformdirs<5,>=3.9.1 (from virtualenv>=20.24.2->pipenv)
42:25 AM:   Downloading platformdirs-4.3.8-py3-none-any.whl.metadata (12 kB)
42:25 AM: Downloading pipenv-2025.0.3-py3-none-any.whl (2.9 MB)
42:25 AM:    ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 2.9/2.9 MB 65.4 MB/s eta 0:00:00
42:25 AM: Downloading packaging-25.0-py3-none-any.whl (66 kB)
42:25 AM: Downloading setuptools-80.9.0-py3-none-any.whl (1.2 MB)
42:25 AM:    ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 1.2/1.2 MB 93.4 MB/s eta 0:00:00
42:25 AM: Downloading virtualenv-20.31.2-py3-none-any.whl (6.1 MB)
42:25 AM:    ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 6.1/6.1 MB 192.5 MB/s eta 0:00:00
42:25 AM: Downloading certifi-2025.6.15-py3-none-any.whl (157 kB)
42:26 AM: Downloading distlib-0.3.9-py2.py3-none-any.whl (468 kB)
42:26 AM: Downloading filelock-3.18.0-py3-none-any.whl (16 kB)
42:26 AM: Downloading platformdirs-4.3.8-py3-none-any.whl (18 kB)
42:26 AM: Installing collected packages: distlib, setuptools, platformdirs, packaging, filelock, certifi, virtualenv, pipenv
42:27 AM: Successfully installed certifi-2025.6.15 distlib-0.3.9 filelock-3.18.0 packaging-25.0 pipenv-2025.0.3 platformdirs-4.3.8 setuptools-80.9.0 virtualenv-20.31.2
42:27 AM: [notice] A new release of pip is available: 24.3.1 -> 25.1.1
42:27 AM: [notice] To update, run: pip install --upgrade pip
42:28 AM: Attempting Ruby version 2.7.2, read from environment
42:28 AM: Using Ruby version 2.7.2
42:29 AM: Started restoring cached go cache
42:29 AM: Finished restoring cached go cache
42:29 AM: go version go1.19.13 linux/amd64
42:29 AM: Using PHP version 8.0
42:30 AM: Started restoring cached Node.js version
42:32 AM: Finished restoring cached Node.js version
42:32 AM: v22.16.0 is already installed.
42:33 AM: Now using node v22.16.0 (npm v10.9.2)
42:33 AM: Enabling Node.js Corepack
42:33 AM: Started restoring cached build plugins
42:33 AM: Finished restoring cached build plugins
42:33 AM: Started restoring cached corepack dependencies
42:33 AM: Finished restoring cached corepack dependencies
42:33 AM: No npm workspaces detected
42:33 AM: Started restoring cached node modules
42:33 AM: Finished restoring cached node modules
42:33 AM: Installing npm packages using npm version 10.9.2
42:34 AM: up to date, audited 540 packages in 770ms
42:34 AM: 274 packages are looking for funding
42:34 AM:   run `npm fund` for details
42:34 AM: found 0 vulnerabilities
42:34 AM: npm packages installed
42:34 AM: Successfully installed dependencies
42:34 AM: Starting build script
42:35 AM: Detected 1 framework(s)
42:35 AM: "next" at version "15.3.4"
42:35 AM: Section completed: initializing
42:37 AM: ​
42:37 AM: Netlify Build                                                 
42:37 AM: ────────────────────────────────────────────────────────────────
42:37 AM: ​
42:37 AM: ❯ Version
42:37 AM:   @netlify/build 33.4.6
42:37 AM: ​
42:37 AM: ❯ Flags
42:37 AM:   accountId: 66d1d0902d36e530c7d461d3
42:37 AM:   baseRelDir: true
42:37 AM:   buildId: 6856d2d4a160d10008ea4110
42:37 AM:   deployId: 6856d2d4a160d10008ea4112
42:37 AM: ​
42:37 AM: ❯ Current directory
42:37 AM:   /opt/build/repo
42:37 AM: ​
42:37 AM: ❯ Config file
42:37 AM:   No config file was defined: using default values.
42:37 AM: ​
42:37 AM: ❯ Context
42:37 AM:   production
42:38 AM: ​
42:38 AM: ❯ Using Next.js Runtime - v5.11.3
42:39 AM: Next.js cache restored
42:39 AM: ​
42:39 AM: Build command from Netlify app                                
42:39 AM: ────────────────────────────────────────────────────────────────
42:39 AM: ​
42:39 AM: $ npm run build
42:40 AM: > next-animated-portfolio@0.1.0 build
42:40 AM: > next build
42:40 AM:  ⚠ Found lockfile missing swc dependencies, run next locally to automatically patch
42:40 AM:    ▲ Next.js 15.3.4
42:40 AM:    Creating an optimized production build ...
42:40 AM:  ⚠ Found lockfile missing swc dependencies, run next locally to automatically patch
42:43 AM:  ⚠ Found lockfile missing swc dependencies, run next locally to automatically patch
42:43 AM:  ⚠ Found lockfile missing swc dependencies, run next locally to automatically patch
42:46 AM:  ✓ Compiled successfully in 3.0s
42:46 AM:    Linting and checking validity of types ...
42:48 AM: Failed to compile.
42:48 AM: 
42:48 AM: src/app/blog/[slug]/page.tsx
42:48 AM: Type error: Type 'PageProps' does not satisfy the constraint 'import("/opt/build/repo/.next/types/app/blog/[slug]/page").PageProps'.
42:48 AM:   Types of property 'params' are incompatible.
42:48 AM:     Type '{ slug: string; }' is missing the following properties from type 'Promise<any>': then, catch, finally, [Symbol.toStringTag]
42:48 AM: Next.js build worker exited with code: 1 and signal: null
42:48 AM: ​
42:48 AM: "build.command" failed                                        
42:48 AM: ────────────────────────────────────────────────────────────────
42:48 AM: ​
42:48 AM:   Error message
42:48 AM:   Command failed with exit code 1: npm run build
42:48 AM: ​
42:48 AM:   Error location
42:48 AM:   In Build command from Netlify app:
42:48 AM:   npm run build
42:48 AM: ​
42:48 AM:   Resolved config
42:48 AM:   build:
42:48 AM:     command: npm run build
42:48 AM:     commandOrigin: ui
42:48 AM:     environment:
42:48 AM:       - STRIPE_SECRET_KEY
42:48 AM:     publish: /opt/build/repo/.next
42:48 AM:     publishOrigin: ui
42:48 AM:   plugins:
42:48 AM:     - inputs: {}
42:48 AM:       origin: ui
42:48 AM:       package: '@netlify/plugin-nextjs'
42:49 AM: Build failed due to a user error: Build script returned non-zero exit code: 2
42:49 AM: Failing build: Failed to build site
42:49 AM: Finished processing build request in 35.267s
42:49 AM: Failed during stage 'building site': Build script returned non-zero exit code: 2

Your Netlify build failed because of a **TypeScript error in your `page.tsx` file**, specifically in:

```
src/app/blog/[slug]/page.tsx
```

### ❌ Error Summary:
```
Type error: Type 'PageProps' does not satisfy the constraint 
'import("/opt/build/repo/.next/types/app/blog/[slug]/page").PageProps'.

Types of property 'params' are incompatible.

Type '{ slug: string; }' is missing the following properties from type 'Promise<any>': then, catch, finally, [Symbol.toStringTag]
```

---

### ✅ Fix It:

This typically means you **accidentally marked `params` as a `Promise`**, or **mismatched the types** in your route file.

Here’s what you need to do:

#### 1. **Check your `PageProps` type** in `page.tsx`:
Make sure it looks something like this:

```ts
interface PageProps {
  params: {
    slug: string;
  };
}
```

Not this:

```ts
interface PageProps {
  params: Promise<{
    slug: string;
  }>;
}
```

> That would cause the error because Next.js is expecting `params` to be a plain object, **not a Promise**.

---

#### 2. **Check your function signature**:

```ts
export default async function Page({ params }: PageProps) {
  const { slug } = params;
  // rest of your code
}
```

The `params` should be used directly. You **should not be doing** `await params`, or anything that implies it’s async.

---

### Optional: Add a Type Hint for Clarity

If you want to use the Next.js built-in types:

```ts
import { Metadata } from 'next';

type Props = {
  params: { slug: string };
};

export async function generateMetadata({ params }: Props): Promise<Metadata> {
  const { slug } = params;
  return {
    title: `Post: ${slug}`,
  };
}

export default function Page({ params }: Props) {
  return <div>Slug is: {params.slug}</div>;
}
```

---

### Bonus Fix: Run Next Locally to Auto-Patch SWC

This build warning showed up multiple times:

```
⚠ Found lockfile missing swc dependencies, run next locally to automatically patch
```

Run this locally:

```bash
npm install
npm run build
```

It will patch your `.lock` file so Netlify won’t complain.

---

### Summary

- ✅ Fix `PageProps` type: `params` should be a plain object, not a `Promise`
- ✅ Ensure you're not using `await` on `params`
- ⚠ Run `next build` locally to fix missing SWC deps

Want me to check your `page.tsx` file? Paste it here and I’ll give you the exact fix.

gpt-4o

write the cline prompt to fix it

Here’s a **CLine prompt** that will fix the TypeScript error in `page.tsx` by correcting the `PageProps` type:

```
fix TypeScript build error in src/app/blog/[slug]/page.tsx — params is typed incorrectly as a Promise or an incompatible type. Update the PageProps interface so that params is a plain object like { slug: string } and make sure it matches the expected Next.js app router pattern. Ensure that no await or async usage is applied to params. Also, run next build locally to patch any missing swc dependencies.
```

---

### Optional: If you're editing with CLIne's file-specific commands, use:

```
edit src/app/blog/[slug]/page.tsx:
Fix the type error where `params` is incorrectly typed as a Promise. 
Change PageProps so that it has:
  interface PageProps {
    params: { slug: string };
  }
Ensure that the component function signature matches this and does not await `params`.
```

Let me know if you're using CLIne with a scripting setup (like `bash`, `node`, or `ollama`) and I can tailor this for automation too.

gpt-4o