Onesignal-flutter-sdk: Pod install fails after following official SDK tutorial

[lifenautjoe]

Description:
Following the Flutter SDK Setup step by step, at step 2.8:

2.8 Open terminal, cd to the /ios directory, and run pod install.

The install fails with the error message

```bash Analyzing dependencies Fetching podspec forFlutterfrom.symlinks/flutter/ios-release Fetching podspec forflutter_secure_storagefrom.symlinks/plugins/flutter_secure_storage/ios Fetching podspec forimage_cropperfrom.symlinks/plugins/image_cropper/ios Fetching podspec forimage_pickerfrom.symlinks/plugins/image_picker/ios Fetching podspec foronesignalfrom.symlinks/plugins/onesignal/ios Fetching podspec forpath_providerfrom.symlinks/plugins/path_provider/ios Fetching podspec forshared_preferencesfrom.symlinks/plugins/shared_preferences/ios Fetching podspec foruni_linksfrom.symlinks/plugins/uni_links/ios Fetching podspec forurl_launcherfrom.symlinks/plugins/url_launcher/ios Fetching podspec forvideo_playerfrom.symlinks/plugins/video_player/ios`
[!] CocoaPods could not find compatible versions for pod "OneSignal":
In Podfile:
OneSignal (< 3.0, >= 2.9.3)

onesignal (from `.symlinks/plugins/onesignal/ios`) was resolved to 1.0.5, which depends on
  OneSignal (< 3.0, >= 2.9.5)

Specs satisfying the OneSignal (< 3.0, >= 2.9.3), OneSignal (< 3.0, >= 2.9.5) dependency were found, but they required a higher minimum deployment target.

[!] Automatically assigning platform ios with version 8.0 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.

[!] Automatically assigning platform ios with version 10.2 on target OneSignalNotificationServiceExtension because no platform was specified. Please specify a platform for this target in your Podfile. See https://guides.cocoapods.org/syntax/podfile.html#platform.
````

Environment

• OneSignal Flutter SDK ^1.0.0 (As in the example)
• Flutter 1.0.0 • channel stable • https://github.com/flutter/flutter.git

[lifenautjoe]

Fixed by running

bash pod repo update

Hope this helps someone else!

[alaindixon]

Thank you :)

[zhangyangsk8]

@lifenautjoe I would like to thank you ~

[dukaric1991]

How can i run pod repo update on codeMagic if anyone knows?

[enricobenedos]

Sometimes run

pod repo update
pod install 

is not enough.
This was my error after updated OneSingal SDK on pubspec.yaml from onesignal_flutter: ^2.0.0 to onesignal_flutter: ^2.1.0:

[!] CocoaPods could not find compatible versions for pod "OneSignal":
  In snapshot (Podfile.lock):
    OneSignal (< 3.0, = 2.10.1, >= 2.9.3)

  In Podfile:
    OneSignal (< 3.0, >= 2.9.3)

    onesignal_flutter (from `.symlinks/plugins/onesignal_flutter/ios`) was resolved to 2.1.0, which depends on
      OneSignal (= 2.11.0)


You have either:
 * out-of-date source repos which you can update with `pod repo update` or with `pod install --repo-update`.
 * changed the constraints of dependency `OneSignal` inside your development pod `onesignal_flutter`.
   You should run `pod update OneSignal` to apply changes you've made.

This is the workaround I used to solve the problem:

cd ios/
pod repo update
rm -rf Podfile.lock Pods
pod install