expo start hangs when opening browser, ignores all input and options

[jessegranger]

Description

expo start hangs, never opens the DevTools in the browser, ignores all input arguments.

Expected Behavior

What actions did I perform?

> expo init blank-template, then choose a Blank Template.

In the resulting directory that is created:

> expo start

What did I expect?

I expect the packager to start, and for the dev tools to open in default browser (Firefox).

Or, an error, if there is some system mis-configuration.

Observed Behavior

> expo start
Starting project at /xxx/blank-template
Expo DevTools is running at http://localhost:19002
Opening DevTools in the browser... (press shift-d to disable)
# expo hangs here forever, no browser is ever opened
# if you manually open a browser and go to http://localhost:19002, it never responds
# pressing shift-d has no effect (prints D in the console, but does not un-hang)
^C
Stopping packager...
Packager stopped.
# Now, the browser opens a new tab with the DevTools url but it is already down

Passing options like --https, are ignored.

> expo start --https
Starting project at /xxx/blank-template
Expo DevTools is running at http://localhost:19002
Opening DevTools in the browser... (press shift-d to disable)
^C

Same output when passing any of the options listed in expo start --help.
Eg, passing --tunnel, --lan, or --localhost, all just open on http://localhost:19002.
No effect from using --dev, --no-dev, --https, --no-https, -a, -i, -w, -c, --web-only, none of these have any effect.

Environment

> expo diagnostics

  Expo CLI 3.0.10 environment info:
    System:
      OS: macOS 10.14.6
      Shell: 3.0.2 - /usr/local/bin/fish
    Binaries:
      Node: 12.10.0 - /usr/local/bin/node
      npm: 6.10.3 - /usr/local/bin/npm
    IDEs:
      Android Studio: 3.5 AI-191.8026.42.35.5791312
      Xcode: 10.3/10G8 - /usr/bin/xcodebuild
    npmPackages:
      expo: ^34.0.1 => 34.0.4
      react: 16.8.3 => 16.8.3
      react-native: https://github.com/expo/react-native/archive/sdk-34.0.0.tar.gz => 0.59.8
    npmGlobalPackages:
      expo-cli: 3.0.10

Default browser is Firefox (69.0).

I tried using bash shell, I tried removing ~/.expo, neither had any effect.

Reproducible Demo

The built-in blank template fails for me.

[jessegranger]

This is actually a bug in the "react-dev-utils" package. I posted a more detailed issue over there.

The gist is: if you have OS X but not "Google Chrome", then expo start will hang.

Link to the underlying issue: https://github.com/zanettin/react-dev-utils/issues/3

Leaving this issue open because it still misbehaves here, the resolution will be to upgrade to whatever version of react-dev-utils fixes the underlying issue.

[aqib1604]

Hello @jessegranger

I am facing same issue @jessegranger let me know if you get any solution for that.
I have upgraded "npm install -g expo-cli" to 3.2.3 but still getting same issue not opening DevTools in chrome browser.

Expo DevTools is running at http://localhost:19002
Opening DevTools in the browser... (press shift-d to disable)

Please help to resolve this issue

[jessegranger]

As a workaround, you can force a different browser using the BROWSER environment variable.

For me, env BROWSER=firefox expo start works.

[brentvatne]

we use the latest version of react-dev-utils, so i suspect this has been resolved