Reputation: 111

Unable to activate Dart Devtools

On opening dart devtools in VS its showing Dart devtools exited with code 255 . I even tried to activating it from terminal in VS by typing flutter pub global activate devtools but its showing could not find a command named “global” for “flutter pub” error again after activating devtools:

Upvotes: 11

Answers (10)

Anupama Kumari

Reputation: 11

If the below response is shown, then type dart devtools in terminal

flutter pub global activate devtools
The current Dart SDK version is 3.2.3.

Because pub global activate depends on devtools any which does not support null safety, version solving failed.

The lower bound of "sdk: '>=2.1.0-dev <3.0.0'" must be 2.12.0 or higher to enable null safety.
For details, see https://dart.dev/null-safety

Upvotes: 1

Mercutio1243

Reputation: 155

Please note that some of the answers here are outdated:

DevTools is shipped as part of the Dart and Flutter SDKs and is no longer shipped on pub. So when you upgrade Flutter, you automatically get the version of DevTools that is shipped with that SDK.

This means, pub commands for DevTools are depreciated, and you should not use legacy commands such as the following:

> flutter pub global activate devtools  
> dart pub global activatedevtools

For me trying them led to various errors. For more information see here: https://github.com/flutter/devtools/issues/7135

Ps: As I do not have enough reputation to comment, I add my learnings as an answer here, hoping that you will avoid this pitfalls.

Upvotes: 0

TijnvdEijnde

Reputation: 301

I tried the above-mentioned solutions, however, none of them seemed to work for me:

flutter pub global activate devtools
The current Dart SDK version is 3.2.3.

Because pub global activate depends on devtools any which does not support null safety, version solving failed.

The lower bound of "sdk: '>=2.1.0-dev <3.0.0'" must be 2.12.0 or higher to enable null safety.
For details, see https://dart.dev/null-safety

I ended up executing dart devtools which opened up the Dev Tools.

For more information: https://docs.flutter.dev/tools/devtools/cli

Upvotes: 8

K D

Reputation: 215

To activate devtools, use this command

dart pub global activate devtools

Upvotes: 1

parmeet singh

Reputation: 79

I am a mac user so you can use this command to enable dart.

export PATH="/Users/<MAC_USER_NAME>/Desktop/developer/flutter/bin/cache/dart-sdk:$PATH"

Upvotes: 0

fpsColton

Reputation: 873

I was experiencing this same issue, and also getting error messages when viewing extension pages

Error loading webview: Error: Could not register service workers: TypeError: Failed to register a ServiceWorker

The solution that fixed both (the error 255 Dart DevTools, and this webview error) was found here (kill all instances of VS Code, then clear VS Code caches).

Upvotes: 0