flutter - 为什么 pubspec environment/sdk/uses "' >=2.7.0 <3.0. 0' "而不是 "^2.7.0 "

Question

诚然，我对semver的理解非常有限。

这个

environment:
  sdk: ^2.7.0

相当于这个

environment:
  sdk: '>=2.7.0 <3.0.0'

包发布严格执行此格式

Package validation found the following error:
* ^ version constraints aren't allowed for SDK constraints since older versions of pub don't support them.
  Expand it manually instead:
  
  environment:
    sdk: ">=2.7.0 <3.0.0"
Sorry, your package is missing a requirement and can't be published yet.

Flutter 使用后者 代替前者 有什么原因吗，

这可以说是更熟悉和 consistent ？

Answer 1

一些定义:

• ^2.7.0是Caret syntax
• >=2.7.0 <3.0.0是Traditional syntax

并且基于documentation :

Because caret syntax was introduced in Dart 1.8.3, it requires an SDK constraint (using traditional syntax) to ensure that older versions of pub don’t try to process it. For example:

environment:
  sdk: '>=1.8.3 <3.0.0'