Document and test a mechanism to require a certain Flutter version to build

[rock3r]

Right now there is no way to specify the required Flutter version in the pubspec.yaml. One should be able to pin the build to a specific version (or commit) of Flutter so that the build is reproducible in the future. Furthermore, there is no way currently to ensure developers working on a shared codebase all use the same version of Flutter, making collaboration on bugfixing and debugging potentially impossible.

tl;dr it would be nice if it were possible to specify the version of Flutter to use just like one could specify the Dart SDK version to use.

[rock3r]

CC @devoncarew

[Hixie]

The current suggestion is to use git submodules to check out the specific version of flutter into the app's repository.

[rock3r]

Yes I'm aware of that, and there's some tools to make it less painful to deal with — submodules aren't exactly user friendly to deal with, in the first place, so that is not a great development experience. Then there's the fact that nowhere in the project file it says what version of flutter the code is coded against. It is a problem because you cannot really rely on any non-code documentation (we all know it gets out of date or irrelevant or misleading quite fast).

[aegis123]

I also believe this should part of the tooling and the project itself and not some external 3rd party like git. Since maybe I want to use mercurial or svn as cvs system and as developer I should have to freedom to do that without having to be forced to use git for instance.

[Hixie]

I think you actually can do this using a flutter SDK constraint:

environment:
  sdk: ">=2.0.0-dev.28.0 <3.0.0"
  flutter: ">=0.1.4 <2.0.0"

For example, see https://github.com/flutter/plugins/blob/master/packages/image_picker/pubspec.yaml

[Hixie]

We should probably document this better.

[Hixie]

And test it.