iphoneXR模拟器启动，报兼容问题

[JayTam]

Flutter版本

Flutter 1.7.8+hotfix.4 • channel stable • https://github.com/flutter/flutter.git
Framework • revision 20e59316b8 (5 weeks ago) • 2019-07-18 20:04:33 -0700
Engine • revision fee001c93f
Tools • Dart 2.4.0

控制台报错信息

Resolving dependencies of `Podfile`
    [!] CocoaPods could not find compatible versions for pod "JCore":
      In snapshot (Podfile.lock):
        JCore (< 3.0.0, = 2.1.1, >= 1.0.0)

      In Podfile:
        jmessage_flutter (from `.symlinks/plugins/jmessage_flutter/ios`) was resolved to 0.0.1, which depends on
          JMessage was resolved to 3.9.0, which depends on
            JCore (< 3.0.0, >= 1.0.0)

    It seems like you've changed the constraints of dependency `JCore` inside your development pod `jmessage_flutter`.
    You should run `pod update JCore` to apply changes you've made.


Error output from CocoaPods:
↳

    [!] The version of CocoaPods used to generate the lockfile (1.7.5) is higher than the version of the current executable (1.7.1). Incompatibility issues may arise.

    [!] Automatically assigning platform `ios` with version `9.3` on target `Runner` because no platform was specified. Please specify a platform for this target in your Podfile. See `https://guides.cocoapods.org/syntax/podfile.html#platform`.