dart 2.19 beta.4 reports incorrect version range

[bsutton]

I have the following pubspec.yaml

name: library
version: 0.0.1
description: A simple command-line application created by dcli
environment: 
  sdk: '>=2.19.0-beta.1 <3.0.0'
dependencies: 
  dcli: 1.36.0
dev_dependencies: 
  lint_hard: ^1.0.0

Note the max sdk is < 3.0.0

When I run dart pub get

dart pub get
Resolving dependencies... 
The current Dart SDK version is 2.19.0-444.4.beta.

Because library requires SDK version >=2.19.0-beta.1 <4.0.0, version solving failed.

Note the upper version is displayed as < 4.0.0 rather than the expected < 3.0.0

FYI:

 dart --version
Dart SDK version: 2.19.0-444.4.beta (beta) (Tue Jan 10 10:24:44 2023 +0000) on "linux_x64"

[srawlins]

@jonasfj @sigurdm does this seem like a pub bug for another repo?

[sigurdm]

Yeah - this is because we decided to extend the compatibility forwards, such that
dart sdk constraints of >=2.12.0 <3.0.0 gets interpreted as >=2.12 <4.0.0.

We only do this for constraints that enable null-safety:
dart sdk constraints of >=2.9.0 <3.0.0 gets interpreted as >=2.9.0 <3.0.0.

The logic was implemented here: #3572

Original issue here: #3554

The intent is that you will not see the rewritten constraint in error messages (after dart 3 such a constraint is always matched with the current sdk) but for dart 2.19 this can happen... I think I did not really consider that case.

I wonder if this is serious enough that we should try to hotfix it for 2.19? The hotfix would probably be to revert #3572 such that it only takes effect in dart 3.

It will never cause a resolution to fail that would otherwise have succeeded, only it will have a confusing error message.

@mit-mit WDYT?

[jonasfj]

@sigurdm, won't this also be a source of confusion in 3.x?

I think at one-point we considered doing:

Because library requires SDK version >=2.19.0-beta.1 <3.0.0 (interpreted as <4.0.0), version solving failed.

I don't recall why we abandoned it, probably it was messy to carry the information around.

Maybe, we could do something like:

The current Dart SDK version is 2.19.0-444.4.beta.
Packages that support null-safety have had SDK constraints <3.0.0 changed to 4.0.0.

Because library requires SDK version >=2.19.0-beta.1 <3.0.0, version solving failed.

Maybe, we can do a better message. But as I recall the "The current Dart SDK version is 2.19.0-444.4.beta." part comes from a "hint" on the incompatibility... Maybe there is a way we can provide another hint.
Something sort with a dart.dev/go/... link that explains all of this might be nice.

[sigurdm]

It is much harder to achieve the error message in dart 3 (because dart 3 is part of the extended range)

We are actually carrying the information around.

I implemented this here https://github.com/dart-lang/pub/blob/master/lib/src/pubspec.dart#L659 . But due to the way we calculate a union of sdk constraints here:

pub/lib/src/solver/package_lister.dart

Line 347 in 12a2af4

var sdkConstraint = await foldAsync<VersionConstraint, PackageId>(

this is not coming through here:

pub/lib/src/solver/incompatibility.dart

Line 134 in 12a2af4

buffer.write('SDK version ${cause.constraint}');

We could probably fix this

[mit-mit]

Yes, I think #3572 should not be in Dart 2.19. That was not intended. @sigurdm can you start a cherry-pick?

[renatoathaydes]

I think this is breaking my package score in pub.dev: https://pub.dev/packages/isolate_current_directory/score

SLVR: fact: isolate_current_directory requires SDK version >=2.19.0 <4.0.0
SLVR: conflict: isolate_current_directory requires SDK version >=2.19.0 <4.0.0
SLVR: Version solving took 0:00:00.029009 seconds.
    | Tried 1 solutions.
FINE: Resolving dependencies finished (0.058s).
ERR : The current Dart SDK version is 2.19.0-444.4.beta.
    | 
    | Because isolate_current_directory requires SDK version >=2.19.0 <4.0.0

My pubspec says:

environment:
  sdk: '>=2.19.0 <3.0.0'

[renatoathaydes]

Or maybe pub.dev's score system needs to upgrade its Dart SDK given it seems to be behind?

[mit-mit]

@renatoathaydes I think this was fixed? I'm seeing 130/140 points on my end...

[renatoathaydes]

@mit-mit ah great, they probably updated the Dart SDK, it was failing lots of things before!

[BaudouinCS]

I'm getting a

This requires the 'records' language feature to be enabled.
Try updating your pubspec.yaml to set the minimum SDK constraint to 2.19.0 or higher, and running 'pub get'.

My pubspec.yaml, post-flutter pub get:

environment:
  sdk: ">=2.19.0 <3.0.2"

Is this linked to this issue?

[mit-mit]

That is unrelated -- it looks like you are previewing the upcoming records feature? In that case you need the lower constraint to be >=2.19.0 AND pass the records experiment flag as the feature still hasn't graduated to beta and thus is still behind a flag.

[sigurdm]

Closing, as this has landed in a stable hotfix.