"npm start" stops immediately when run as background job

[moos]

Describe the bug

On a fresh install of CRA, running npm start & (in background) stops the job after hitting the Enter key.

Did you try recovering your dependencies?

n/a

Which terms did you search for in User Guide?

"background"

Environment

current version of create-react-app: 3.4.1
running from /Users/foo/.npm/_npx/78633/lib/node_modules/create-react-app

System:
OS: macOS 10.15.4
CPU: (16) x64 Intel(R) Core(TM) i9-9880H CPU @ 2.30GHz
Binaries:
Node: 10.20.1 - /var/folders/6v/sfby3s_d0l320yd3hyblj3bc0000gq/T/fnm-shell-7483721/bin/node
Yarn: Not Found
npm: 6.14.4 - /var/folders/6v/sfby3s_d0l320yd3hyblj3bc0000gq/T/fnm-shell-7483721/bin/npm
Browsers:
Chrome: 81.0.4044.129
Firefox: Not Found
Safari: 13.1
npmPackages:
react: ^16.13.1 => 16.13.1
react-dom: ^16.13.1 => 16.13.1
react-scripts: 3.4.1 => 3.4.1
npmGlobalPackages:
create-react-app: Not Found

Steps to reproduce

(Write your steps here:)

1. npx create-react-app my-app
2. cd my-app
3. npm start &
4. Hit Enter key

It should start the dev server and run it in the (shell) background. It used to work like that.

Actual behavior

It immediately stops the job:

[1]+  Stopped                 npm start

Reproducible demo

n/a

[moos]

More info: I believe this is caused by #7203. When I remove that, it runs in the background. The culprit seems to be this line.

Fix for #8688 does not resolve this issue.

[cipriancaba]

I have the same issue when running start in a yarn monorepo, starting multiple cra apps

[jannikbuschke]

+1

[backus]

Same. Central to my dev workflow too, so I tinkered a bit. I have a monorepo where a bash script launches about 6 different processes, backgrounds each, then calls wait on each.

Workaround

I changed

BROWSER=none yarn start &

to

BROWSER=none yarn start | cat - &

in my bash script and now create-react-app behaves normally again, albeit without colorized output

[stale]

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[stale]

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