Issue 1:
Steps to Reproduce

Follow the steps to integrate Google Sign In to iOS app from here

Logs

flutter run output

➜ flutter_todo flutter run -d iP8+P
Launching lib/main.dart on iP8+P in debug mode...
Automatically signing iOS for device deployment using specified development team in Xcode project: S29F39HXPA
Running pod install... 1.3s
Running Xcode clean... 1.4s
Starting Xcode build...
├─Building Dart code... 3.4s
├─Assembling Flutter resources... 4.1s
└─Compiling, linking and signing... 0.7s
Xcode build done 15.5s
Failed to build iOS app
Error output from Xcode build:
↳
** BUILD FAILED **

Xcode's output:
↳
=== BUILD TARGET google_sign_in OF PROJECT Pods WITH CONFIGURATION Debug ===
/Users/kalehv/.pub-cache/hosted/pub.dartlang.org/google_sign_in-2.1.0/ios/Classes/GoogleSignInPlugin.m:111:41: warning: 'UIApplicationOpenURLOptionsSourceApplicationKey' is only available on iOS 9.0 or newer [-Wunguarded-availability]
NSString *sourceApplication = options[UIApplicationOpenURLOptionsSourceApplicationKey];
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In module 'UIKit' imported from /Users/kalehv/dev/flutter_todo/ios/Pods/Target Support Files/google_sign_in/google_sign_in-prefix.pch:2:
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS11.2.sdk/System/Library/Frameworks/UIKit.framework/Headers/UIApplication.h:534:51: note: 'UIApplicationOpenURLOptionsSourceApplicationKey' has been explicitly marked partial here
UIKIT_EXTERN UIApplicationOpenURLOptionsKey const UIApplicationOpenURLOptionsSourceApplicationKey NS_AVAILABLE_IOS(9_0); // value is an NSString containing the bundle ID of the originating application
^
/Users/kalehv/.pub-cache/hosted/pub.dartlang.org/google_sign_in-2.1.0/ios/Classes/GoogleSignInPlugin.m:111:41: note: enclose 'UIApplicationOpenURLOptionsSourceApplicationKey' in an @available check to silence this warning
NSString *sourceApplication = options[UIApplicationOpenURLOptionsSourceApplicationKey];
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/Users/kalehv/.pub-cache/hosted/pub.dartlang.org/google_sign_in-2.1.0/ios/Classes/GoogleSignInPlugin.m:112:27: warning: 'UIApplicationOpenURLOptionsAnnotationKey' is only available on iOS 9.0 or newer [-Wunguarded-availability]
id annotation = options[UIApplicationOpenURLOptionsAnnotationKey];
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In module 'UIKit' imported from /Users/kalehv/dev/flutter_todo/ios/Pods/Target Support Files/google_sign_in/google_sign_in-prefix.pch:2:
/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS11.2.sdk/System/Library/Frameworks/UIKit.framework/Headers/UIApplication.h:535:51: note: 'UIApplicationOpenURLOptionsAnnotationKey' has been explicitly marked partial here
UIKIT_EXTERN UIApplicationOpenURLOptionsKey const UIApplicationOpenURLOptionsAnnotationKey NS_AVAILABLE_IOS(9_0); // value is a property-list typed object corresponding to what the originating application passed in UIDocumentInteractionController's annotation property
^
/Users/kalehv/.pub-cache/hosted/pub.dartlang.org/google_sign_in-2.1.0/ios/Classes/GoogleSignInPlugin.m:112:27: note: enclose 'UIApplicationOpenURLOptionsAnnotationKey' in an @available check to silence this warning
id annotation = options[UIApplicationOpenURLOptionsAnnotationKey];
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
2 warnings generated.
=== BUILD TARGET google_sign_in OF PROJECT Pods WITH CONFIGURATION Debug ===
ld: warning: -undefined dynamic_lookup is deprecated on iOS
=== BUILD TARGET Runner OF PROJECT Runner WITH CONFIGURATION Debug ===
The use of Swift 3 @objc inference in Swift 4 mode is deprecated. Please address deprecated @objc inference warnings, test your code with “Use of deprecated Swift 3 @objc inference” logging enabled, and then disable inference by changing the "Swift 3 @objc Inference" build setting to "Default" for the "Runner" target.
=== BUILD TARGET Runner OF PROJECT Runner WITH CONFIGURATION Debug ===
/Users/kalehv/dev/flutter_todo/ios/Runner/GeneratedPluginRegistrant.m:6:9: fatal error: 'google_sign_in/GoogleSignInPlugin.h' file not found
#import <google_sign_in/GoogleSignInPlugin.h>
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.
Could not build the precompiled application for the device.

Error launching application on iP8+P.

flutter analyze output

➜ flutter_todo flutter analyze
Analyzing /Users/kalehv/dev/flutter_todo...
No issues found!
Ran in 4.9s

Flutter Doctor

flutter doctor -v output (Device IDs redacted)

Note - I am not using IntelliJ IDEA. I am using Android Studio instead.

➜ flutter_todo flutter doctor -v
[✓] Flutter (on Mac OS X 10.13.3 17D102, locale en-US, channel beta)
• Flutter version 0.1.4 at /Users/kalehv/Library/flutter
• Framework revision f914e701c5 (8 days ago), 2018-02-19 21:12:17 +0000
• Engine revision 13cf22c284
• Dart version 2.0.0-dev.27.0-flutter-0d5cf900b0

[✓] Android toolchain - develop for Android devices (Android SDK 27.0.3)
• Android SDK at /Users/kalehv/Library/Android/sdk
• Android NDK at /Users/kalehv/Library/Android/sdk/ndk-bundle
• Platform android-27, build-tools 27.0.3
• ANDROID_HOME = /Users/kalehv/Library/Android/sdk
• Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-915-b08)

[✓] iOS toolchain - develop for iOS devices (Xcode 9.2)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Xcode 9.2, Build version 9C40b
• ios-deploy 1.9.2
• CocoaPods version 1.4.0

[✓] Android Studio
• Android Studio at /Applications/Android Studio 3.0 Preview.app/Contents
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-915-b01)

[✓] Android Studio (version 3.0)
• Android Studio at /Applications/Android Studio.app/Contents
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-915-b08)

[!] IntelliJ IDEA Community Edition (version 2017.3.4)
✗ Flutter plugin not installed; this adds Flutter specific functionality.
✗ Dart plugin not installed; this adds Dart specific functionality.
• For information about installing plugins, see
https://flutter.io/intellij-setup/#installing-the-plugins

[✓] VS Code (version 1.20.1)
• VS Code at /Applications/Visual Studio Code.app/Contents
• Dart Code extension version 2.9.0

[✓] Connected devices
• iP8+P • XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX • ios • iOS 11.2.5
• iPhone X • XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXX • ios • iOS 11.2 (simulator)

! Doctor found issues in 1 category.

As you can see, for some reason, I am not able to add any dependency package and run the app for iOS. This issue is not specific to only google_sign_in.

Working fine on Android.

Issue 2:
Steps to Reproduce

set -x

mkdir -p Made_Podfiles_use_symlinks_to_local_pods_NOT_WORKING/
pushd Made_Podfiles_use_symlinks_to_local_pods_NOT_WORKING/

flutter create -t plugin -i swift --org com.failed failed > /dev/null
pushd failed/example
flutter build ios --debug
popd

flutter create -t plugin -i swift --org com.success success > /dev/null
pushd success/example
wget -q https://raw.githubusercontent.com/mravn-google/flutter/3723ec0383f79420486bb4ee5acf06ebd190b5cf/packages/flutter_tools/templates/cocoapods/Podfile-swift
cp Podfile-swift ios/Podfile
flutter build ios --debug
popd

popd

Flutter Doctor

➜ ~ flutter doctor -v
[✓] Flutter (Channel master, v0.1.8-pre.43, on Mac OS X 10.13.3 17D102, locale en-KR)
• Flutter version 0.1.8-pre.43 at /Users/?????/flutter
• Framework revision fe334e1652 (3 hours ago), 2018-03-02 17:54:51 -0800
• Engine revision 97b22348c8
• Dart version 2.0.0-dev.32.0.flutter-ee15c8eb68

[✓] Android toolchain - develop for Android devices (Android SDK 27.0.3)
• Android SDK at /Users/?????/Library/Android/sdk
• Android NDK location not configured (optional; useful for native profiling support)
• Platform android-27, build-tools 27.0.3
• ANDROID_HOME = /Users/?????/Library/Android/sdk
• Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-915-b08)
• All Android licenses accepted.

[✓] iOS toolchain - develop for iOS devices (Xcode 9.2)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Xcode 9.2, Build version 9C40b
• ios-deploy 1.9.2
• CocoaPods version 1.3.1

[✓] Android Studio (version 3.0)
• Android Studio at /Applications/Android Studio.app/Contents
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-915-b08)

[✓] IntelliJ IDEA Community Edition (version 2017.3.4)
• IntelliJ at /Applications/IntelliJ IDEA CE.app
• Flutter plugin version 22.1.2
• Dart plugin version 173.4548.30

[✓] VS Code
• VS Code at /Applications/Visual Studio Code.app/Contents
• Dart Code extension version 2.8.0

[✓] Connected devices (1 available)
• ????????????????????????????????????? • ios • iOS 11.2.6

• No issues found!