Stuck on `Creating an optimized production build` forever when development server is running

Verify canary release

• I verified that the issue exists in Next.js canary release

Provide environment information

Operating System: Platform: win32 Arch: x64 Version: Windows 10 Pro Binaries: Node: 16.13.0 npm: N/A Yarn: N/A pnpm: 6.24.0-1 Relevant packages: next: 12.1.4 react: 17.0.2 react-dom: 17.0.2

What browser are you using? (if relevant)

No response

How are you deploying your application? (if relevant)

No response

Describe the Bug

I had my development server running in the background without me remembering and I wanted to build my app using next build, that’s what I’ve got:

$ yarn next build
yarn run v1.22.17
$ C:\development\activity-builder\node_modules\.bin\next build
info  - Loaded env from C:\development\activity-builder\.env
info  - Checking validity of types  
warn  - The Next.js plugin was not detected in your ESLint configuration. See https://nextjs.org/docs/basic-features/eslint#migrating-existing-config

./src/components/Activities/ActivityQuestions/DynamicQuestionTypes/MultipleChoice.tsx  
68:40  Warning: Forbidden non-null assertion.  @typescript-eslint/no-non-null-assertion
69:22  Warning: Forbidden non-null assertion.  @typescript-eslint/no-non-null-assertion

./src/components/Activities/ActivityQuestions/Question.tsx
102:13  Warning: Unexpected console statement.  no-console

info  - Need to disable some ESLint rules? Learn more here: https://nextjs.org/docs/basic-features/eslint#disabling-rules
info  - Creating an optimized production build  

And I was stuck for 30 minutes on info - Creating an optimized production build without any indication of anything being wrong, I noticed that the development server was running, after I’ve shut it down and ran next build again It compiled successfully.

Expected Behavior

• Run next build to compile the app for production even when I’m running the development server.

  OR

• Notify me that the development server is running and needs to be shut down before running next build, that’s in case running next build when next is running isn’t possible.

Link to reproduction

https://github.com/YassinEldeeb/Next.js-starter

To Reproduce

1. Run next for the development server.
2. Then run next build while the development server is running.

Note: It’s not specific to the repository linked above.

[farro97]

Make sure you don’t run development and build the at the same time. I got my build running forever till I closed my dev server and it completes my build process.

[LordOfTheThunder]

Mine was solved when downgrading from next 13 to next 12.2