[dwds/webdev] Latest `-dev` SDK constraint allows for 3.1.0 stable without new DDC debugger API

[parlough]

For some reason, changes that landed in 3.1.0-263.0-dev through 3.1.0-348.0-dev weren't part of Dart 3.1.0 stable. As a result, the new DDC runtime debugger API (which landed during this period) is not available for users of a stable SDK.

However, the SDK constraint of package:dwds and package:webdev of >=3.1.0-340.0.dev which is correct for -dev releases, also allows for a 3.1.0 stable SDK without the changes. So if you have a 3.1.X stable Dart version and run dart pub global activate webdev resolution will allow for package:webdev:3.0.7, but once debugging an app, you will get issues due to the incompatibilities.

Steps to reproduce:

1. Use a stable Dart 3.1.0 SDK: 3.1.0 or 3.1.1 currently.
2. Create a new project: dart create -t web my_app
3. Debug it with webdev with your preferred mechanism: webdev serve --debug
4. Add a breakpoint and debug main() and try to evaluate something to get an error.

An example resulting error when trying to evaluate main

[WARNING] Library org-dartlang-app:///web/main.dart is not loaded. This can happen for unreferenced libraries.
[WARNING] Failed to evaluate expression 'main'. 
[INFO] Unexpected error from chrome devtools:
text: Uncaught
exception:
  preview: null
  description: TypeError: dart.getFunctionMetadata is not a function
    at Function.<anonymous> (<anonymous>:4:21)
  type: object
  value: null
attempted JS eval: `      function() {
        const sdk = require('dart_sdk');
        const dart = sdk.dart;
        return dart.getFunctionMetadata(this);
      }
    `
stack trace:
()  3:20
:#0      handleErrorIfPresent (package:dwds/src/utilities/server.dart:91:5)
dart-lang/webdev#1      FunctionMetaData.metaDataFor (package:dwds/src/debugging/metadata/function.dart:36:5)
<asynchronous suspension>
dart-lang/webdev#2      StackZoneSpecification._registerUnaryCallback.<anonymous closure> (package:stack_trace/src/stack_zone_specification.dart:127:15)
<asynchronous suspension>

Related discussion: #53298 (comment)

[parlough]

Note that isn't an issue with these packages themselves, more of something confusing happening with the 3.1.0 dev releases. However, since 3.1.0 stable is already out, it seems it has to be fixed in webdev, with a new release with the updated constraint and either a retraction of 3.0.7 or a hotfix 3.0.7 release with a lowered dwds version.

[annagrin]

Thanks @parlough for reporting this, and for the workaround fixing it in webdev.

Looks like an issue with the SDK 3.1.0 release? Transferring to the sdk repo. Please advise how to handle out-of-order releases in the future.

[annagrin]

/cc @sigmundch

[elliette]

Just discussed this with @annagrin, after dart-lang/webdev#2207 has landed we will need to:

• Release Webdev with the new constraints
• Release DWDS with the new constraints (not strictly necessary, we verified that Flutter main which is using DWDS with the bad version constraint is already on Dart 3.2.0, however doing so is still a good idea)
• Release a hotfix of Webdev with DWDS pinned to 19.0.2. This means we don't need to retract 3.0.7, but instead can tell users to run dart pub global activate to get the latest version Webdev

[parlough]

Sounds like a plan. Thanks for following up!

[elliette]

The hotfix release of Webdev has been published: https://pub.dev/packages/webdev/versions/3.0.7+1 Running dart pub global activate webdev should fetch this latest version.