Issue 1:
We currently can't update to a new Dart SDK pending fixes in a few dependent packages. This meta issue tracks progress.

Background: A recent change in the yaml package now treats duplicate map entries as an error which bubbles up through pub if you have an offending pubspec. The rub is that there are packages out there on which we depend, json_schema, for example, that in fact contain duplicate entries.

[~/src/git/clones/flutter] (master) $ flutter update-packages --upgrade
Building flutter tool...
Error on line 27, column 3 of /Users/pquitslund/.pub-cache/hosted/pub.dartlang.org/json_schema-1.0.3/pubspec.yaml: Duplicate mapping key.
yaml: "^2.1.0"

Next steps.

To get us on track we need:

json_schema fixed

json_schema published

id fixed [DEP DROPPED]

id published [DEP DROPPED]

ebisu fixed [DEP DROPPED]

ebisu published [DEP DROPPED]

Then:

land new Dart SDK in flutter tools (#6861)

ping #5865 to let us know we can try const asserts again

Finally:

fix the uploaded json_schema to not include any references to drudge (@patefacio)

FYI @abarth @Hixie (for why SDK rolls have stalled)

Issue 2:
It seems like there are conflicts between GoogleMobileVision and GoogleMobileVision?

Getting errors when building Flutter ios:

duplicate symbol _OBJC_IVAR_$_MDMPasscodeCache._localAuthenticationInfo in: /Volumes/flutter/ios/Pods/GoogleMobileVision/Detector/Frameworks/GoogleMobileVision.framework/GoogleMobileVision(MDMPasscodeCache_f189776e75765630b82721fafea64052.o) /Volumes/flutter/ios/Pods/GoogleSignIn/Frameworks/GoogleSignIn.framework/GoogleSignIn(MDMPasscodeCache_42de90102bb6814d03833694aafcc99d.o) duplicate symbol _OBJC_IVAR_$_MDMPasscodeCache._keychainInfo in: /Volumes/flutter/ios/Pods/GoogleMobileVision/Detector/Frameworks/GoogleMobileVision.framework/GoogleMobileVision(MDMPasscodeCache_f189776e75765630b82721fafea64052.o) /Volumes/flutter/ios/Pods/GoogleSignIn/Frameworks/GoogleSignIn.framework/GoogleSignIn(MDMPasscodeCache_42de90102bb6814d03833694aafcc99d.o) duplicate symbol _OBJC_IVAR_$_MDMPasscodeCache._hasLocalAuthentication in: /Volumes/flutter/ios/Pods/GoogleMobileVision/Detector/Frameworks/GoogleMobileVision.framework/GoogleMobileVision(MDMPasscodeCache_f189776e75765630b82721fafea64052.o) /Volumes/flutter/ios/Pods/GoogleSignIn/Frameworks/GoogleSignIn.framework/GoogleSignIn(MDMPasscodeCache_42de90102bb6814d03833694aafcc99d.o) duplicate symbol _OBJC_IVAR_$_MDMPasscodeCache._hasKeychain in: /Volumes/flutter/ios/Pods/GoogleMobileVision/Detector/Frameworks/GoogleMobileVision.framework/GoogleMobileVision(MDMPasscodeCache_f189776e75765630b82721fafea64052.o) /Volumes/flutter/ios/Pods/GoogleSignIn/Frameworks/GoogleSignIn.framework/GoogleSignIn(MDMPasscodeCache_42de90102bb6814d03833694aafcc99d.o) duplicate symbol _OBJC_IVAR_$_MDMPasscodeCache._cachedState in: /Volumes/flutter/ios/Pods/GoogleMobileVision/Detector/Frameworks/GoogleMobileVision.framework/GoogleMobileVision(MDMPasscodeCache_f189776e75765630b82721fafea64052.o) /Volumes/flutter/ios/Pods/GoogleSignIn/Frameworks/GoogleSignIn.framework/GoogleSignIn(MDMPasscodeCache_42de90102bb6814d03833694aafcc99d.o) duplicate symbol _OBJC_IVAR_$_MDMPasscodeCache._keychainExpireTime in: /Volumes/flutter/ios/Pods/GoogleMobileVision/Detector/Frameworks/GoogleMobileVision.framework/GoogleMobileVision(MDMPasscodeCache_f189776e75765630b82721fafea64052.o) /Volumes/flutter/ios/Pods/GoogleSignIn/Frameworks/GoogleSignIn.framework/GoogleSignIn(MDMPasscodeCache_42de90102bb6814d03833694aafcc99d.o) duplicate symbol _OBJC_CLASS_$_MDMPasscodeCache in: /Volumes/flutter/ios/Pods/GoogleMobileVision/Detector/Frameworks/GoogleMobileVision.framework/GoogleMobileVision(MDMPasscodeCache_f189776e75765630b82721fafea64052.o) /Volumes/flutter/ios/Pods/GoogleSignIn/Frameworks/GoogleSignIn.framework/GoogleSignIn(MDMPasscodeCache_42de90102bb6814d03833694aafcc99d.o) duplicate symbol _OBJC_METACLASS_$_MDMPasscodeCache in: /Volumes/flutter/ios/Pods/GoogleMobileVision/Detector/Frameworks/GoogleMobileVision.framework/GoogleMobileVision(MDMPasscodeCache_f189776e75765630b82721fafea64052.o) /Volumes/flutter/ios/Pods/GoogleSignIn/Frameworks/GoogleSignIn.framework/GoogleSignIn(MDMPasscodeCache_42de90102bb6814d03833694aafcc99d.o) duplicate symbol _OBJC_IVAR_$_MDMPasscodeCache._hasEnteredBackground in: /Volumes/flutter/ios/Pods/GoogleMobileVision/Detector/Frameworks/GoogleMobileVision.framework/GoogleMobileVision(MDMPasscodeCache_f189776e75765630b82721fafea64052.o) /Volumes/flutter/ios/Pods/GoogleSignIn/Frameworks/GoogleSignIn.framework/GoogleSignIn(MDMPasscodeCache_42de90102bb6814d03833694aafcc99d.o) duplicate symbol _OBJC_IVAR_$_MDMPasscodeState._status in: /Volumes/flutter/ios/Pods/GoogleMobileVision/Detector/Frameworks/GoogleMobileVision.framework/GoogleMobileVision(MDMPasscodeState_d2697588db599ad1e82d46f342216cee.o) /Volumes/flutter/ios/Pods/GoogleSignIn/Frameworks/GoogleSignIn.framework/GoogleSignIn(MDMPasscodeState_adbe96d99863168799049cc0f0164c6d.o) duplicate symbol _OBJC_IVAR_$_MDMPasscodeState._info in: /Volumes/flutter/ios/Pods/GoogleMobileVision/Detector/Frameworks/GoogleMobileVision.framework/GoogleMobileVision(MDMPasscodeState_d2697588db599ad1e82d46f342216cee.o) /Volumes/flutter/ios/Pods/GoogleSignIn/Frameworks/GoogleSignIn.framework/GoogleSignIn(MDMPasscodeState_adbe96d99863168799049cc0f0164c6d.o) duplicate symbol _OBJC_CLASS_$_MDMPasscodeState in: /Volumes/flutter/ios/Pods/GoogleMobileVision/Detector/Frameworks/GoogleMobileVision.framework/GoogleMobileVision(MDMPasscodeState_d2697588db599ad1e82d46f342216cee.o) /Volumes/flutter/ios/Pods/GoogleSignIn/Frameworks/GoogleSignIn.framework/GoogleSignIn(MDMPasscodeState_adbe96d99863168799049cc0f0164c6d.o) duplicate symbol _OBJC_METACLASS_$_MDMPasscodeState in: /Volumes/flutter/ios/Pods/GoogleMobileVision/Detector/Frameworks/GoogleMobileVision.framework/GoogleMobileVision(MDMPasscodeState_d2697588db599ad1e82d46f342216cee.o) /Volumes/flutter/ios/Pods/GoogleSignIn/Frameworks/GoogleSignIn.framework/GoogleSignIn(MDMPasscodeState_adbe96d99863168799049cc0f0164c6d.o) ld: 13 duplicate symbols for architecture x86_64 clang: error: linker command failed with exit code 1 (use -v to see invocation)

pubspec.yaml
name: myapp
description: A new Flutter project to enter and tract Renal patient data.
version: 0.4.1+1

dependencies:
flutter:
sdk: flutter
flutter_localizations:
sdk: flutter
firebase_auth: ">=0.5.20"
google_sign_in: "3.0.5"
# google_sign_in: "^3.0.5"

# The following adds the Cupertino Icons font to your application.
# Use with the CupertinoIcons class for iOS style icons.
cupertino_icons: ^0.1.2
intl: ^0.15.7

# Peter add
cloud_firestore: "0.8.0"
#
firebase_storage: ">=1.0.2"
#firebase_admob: ">=0.6.1"
#firebase_analytics: ">=1.0.3"
image_picker: ^0.4.6
path_provider: ^0.4.1
date_format: ^1.0.5
numberpicker: ^0.1.6
progress_image: "^0.0.1"
qr_mobile_vision: "0.0.7"
qr_flutter: ^1.1.3
flutter_native_image:
git: https://github.com/btastic/flutter_native_image.git
connectivity: ^0.3.1
#firebase_messaging: ">=2.0.0"
package_info: ^0.3.2
share: ^0.5.3
url_launcher: ^3.0.3
flutter_walkthrough: ^0.0.1

dev_dependencies:
flutter_test:
sdk: flutter

# For information on the generic Dart part of this file, see the
# following page: https://www.dartlang.org/tools/pub/pubspec

# The following section is specific to Flutter.
flutter:

# The following line ensures that the Material Icons font is
# included with your application, so that you can use the icons in
# the material Icons class.
uses-material-design: true

# To add assets to your application, add an assets section, like this:
# assets:
# - images/a_dot_burr.jpeg
# - images/a_dot_ham.jpeg
assets:

flutter doctor -v
[✓] Flutter (Channel master, v0.9.4-pre.31, on Mac OS X 10.14 18A391, locale en-SG)
• Flutter version 0.9.4-pre.31 at /Users/peterlum/dev/flutter
• Framework revision 52697ef962 (22 hours ago), 2018-09-26 07:57:05 +0200
• Engine revision 38a646e14c
• Dart version 2.1.0-dev.5.0.flutter-4cf2d3990b

[✓] Android toolchain - develop for Android devices (Android SDK 27.0.3)
• Android SDK at /Applications/AndroidDev/sdk
• Android NDK at /Applications/AndroidDev/sdk/ndk-bundle
• Platform android-27, build-tools 27.0.3
• ANDROID_HOME = /Applications/AndroidDev/sdk
• Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 1.8.0_112-release-b06)
• All Android licenses accepted.

[✓] iOS toolchain - develop for iOS devices (Xcode 10.0)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Xcode 10.0, Build version 10A255
• ios-deploy 1.9.2
• CocoaPods version 1.5.3

[✓] Android Studio
• Android Studio at /Applications/Android Studio 3.3.app/Contents
✗ Flutter plugin not installed; this adds Flutter specific functionality.
✗ Dart plugin not installed; this adds Dart specific functionality.
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1248-b01)

[✓] Android Studio (version 2.3)
• Android Studio at /Applications/Android Studio.app/Contents
✗ Flutter plugin version 12.1 - the recommended minimum version is 16.0.0
• Dart plugin version 162.2924
• Java version OpenJDK Runtime Environment (build 1.8.0_112-release-b06)

[✓] VS Code (version 1.27.2)
• VS Code at /Applications/Visual Studio Code.app/Contents
• Flutter extension version 2.18.0

[✓] Connected devices (1 available)
• LG D855 • LGD855a710c089 • android-arm • Android 5.0 (API 21)

• No issues found!