next build stuck on "Checking validity of types..."

What version of Next.js are you using?

12.0.3

What version of Node.js are you using?

16.11.0

What browser are you using?

Chrome

What operating system are you using?

Linux

How are you deploying your application?

Vercel

Describe the Bug

next build keeps getting stuck on " Checking validity of types…" forever. I tried downgrading next’s version to 10.1.3 (my previous project uses this version and the build command works) but it still has the same issue.

Expected Behavior

next build should generate the build files.

To Reproduce

1. Clone this repo
2. cd into the client directory and run yarn build (make sure ignoreBuildErrors is set to false in the next config) The console shows "Checking validity of types… "

[balazsorban44]

We tried profiling the build process in terms of both memory and CPU usage first which showed unusual numbers, but we couldn’t figure out where the issue was.

So I started manually trying to remove all file files first, and slowly adding them back until it froze the build process. At the end, whenever I toggled that extends, I could reproduce the problem consistently.

I saw your post on mui. I recommend you give them as much information as possible in the description itself to help them help you much faster.

[balazsorban44]

Hi @karan316 upon inspection, I have found multiple errors that would fail the compilation:

What freezes up the type checking though seems to be coming from here, when extends MaterialButtonProps is used:

https://github.com/karan316/Placement-Portal/blob/dabe17073c5d4267be8feb3c0cedcf5b2fd5701c/client/components/Button/index.tsx#L2-L10

I’m not really sure yet why that would be an issue, as changing the marked section to this will pass the type checking:

import MaterialButton, { LoadingButtonProps as MaterialButtonProps } from "@mui/lab/LoadingButton";
import { styled } from "@mui/system";

interface ButtonProps { // <- notice I removed the extends part
	text: string;
	rounded?: boolean;
}

const Button = ({ text, variant, onClick, rounded, ...props }: ButtonProps & any) => {

I recommend you post this at https://github.com/mui-org/material-ui as well and link back to this issue. They might have an idea of why this is happening.