Flutter pub get Gives error message whenever .yaml file is changed-CodePudding

The orignal pubspec.yaml files works fine when generated through "flutter create {project_name}" but suppose I want to try to add a dependency such as fluttertoast it gives error message

description: A new Flutter project.

publish_to: 'none' # Remove this line if you wish to publish to pub.dev
version: 1.0.0 1

environment:
  sdk: '>=2.18.0-170.0.dev <3.0.0'
  flutter:
    sdk: flutter

    cupertino_icons: ^1.0.2
    fluttertoast: ^8.0.9
    dev_dependencies:
      flutter_test:
        sdk: flutter
        flutter_lints: ^2.0.0
        flutter:

          uses-material-design: true

This gives the error:

Error on line 10, column 5 of pubspec.yaml: A version constraint must be a string.
   ╷
10 │ ┌     sdk: flutter
11 │ │ 
12 │ │     cupertino_icons: ^1.0.2
13 │ │     fluttertoast: ^8.0.9
14 │ │ 
15 │ │     dev_dependencies:
16 │ │       flutter_test:
17 │ │         sdk: flutter
18 │ │         flutter_lints: ^2.0.0
19 │ │         flutter:
20 │ │ 
21 │ └           uses-material-design: true
   ╵
Running "flutter pub get" in textfield...                               
pub get failed (65;    ╵)

And know even if I delete the fluttertoast dependency

It still results in the error

Error on line 10, column 5 of pubspec.yaml: A version constraint must be a string.
   ╷
10 │ ┌     sdk: flutter
11 │ │ 
12 │ │     cupertino_icons: ^1.0.2
13 │ │       #    fluttertoast: ^8.0.9
14 │ │ 
15 │ │     dev_dependencies:
16 │ │       flutter_test:
17 │ │         sdk: flutter
18 │ │         flutter_lints: ^2.0.0
19 │ │         flutter:
20 │ │ 
21 │ └           uses-material-design: true
   ╵
Running "flutter pub get" in textfield...                               
pub get failed (65;    ╵)

flutter --version output -->

Flutter 3.1.0-0.0.pre.1112 • channel master • https://github.com/flutter/flutter.git
Framework • revision 8294d9e91e (24 hours ago) • 2022-06-05 13:38:04 -0400
Engine • revision 9e4f372577
Tools • Dart 2.18.0 (build 2.18.0-170.0.dev) • DevTools 2.14.0

CodePudding user response：

Yaml is indent sensitive. Easiest way to add a package is to run `flutter pub add fluttertoast' in terminal. To fix the error that you are facing make the indentation of flutter toast same as flutter in pubspec.yaml

dependencies:
  flutter:
    sdk: flutter
  cupertino_icons: any
  flutter toast : ^8.0.9

CodePudding user response：

I think you just missed dependencies: before sdk:.

Set it like this:

environment:
  sdk: '>=2.15.0 <3.0.0'

dependencies:
  flutter:
    sdk: flutter

  cupertino_icons: ^1.0.4

Refer this example for more details about it.