iOs build fails with FacebookLogin package

Question

I'm currently using the Facebook Login package for Flutter for a Flutter app that I'm developing and I'm having problems with building it in iOs.

I've followed all the steps in the guide and works fine in Android but when I try to run it in iOs simulator I have this output

Launching lib/main.dart on iPhone X in debug mode...
Running pod install...
Starting Xcode build...
Xcode build done.                                            3.0s
Failed to build iOS app
Error output from Xcode build:
↳
    ** BUILD FAILED **

Xcode's output:
↳
    In file included from /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/Internal/AppEvents/FBSDKPaymentObserver.m:23:
    In file included from /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/Internal/AppEvents/FBSDKAppEvents+Internal.h:19:
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/FBSDKAppEvents.h:33:19: warning: pointer is missing a nullability type specifier (_Nonnull, _Nullable, or _Null_unspecified) [-Wnullability-completeness]
    FOUNDATION_EXPORT NSNotificationName const FBSDKAppEventsLoggingResultNotification;
                      ^
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/FBSDKAppEvents.h:33:19: note: insert '_Nullable' if the pointer may be null
    FOUNDATION_EXPORT NSNotificationName const FBSDKAppEventsLoggingResultNotification;
                      ^
                                         _Nullable
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/FBSDKAppEvents.h:33:19: note: insert '_Nonnull' if the pointer should never be null
    FOUNDATION_EXPORT NSNotificationName const FBSDKAppEventsLoggingResultNotification;
                      ^
                                         _Nonnull
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/FBSDKAppEvents.h:700:13: warning: pointer is missing a nullability type specifier (_Nonnull, _Nullable, or _Null_unspecified) [-Wnullability-completeness]
    + (NSString *)getUserData;
                ^
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/FBSDKAppEvents.h:700:13: note: insert '_Nullable' if the pointer may be null
    + (NSString *)getUserData;
                ^
                 _Nullable
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/FBSDKAppEvents.h:700:13: note: insert '_Nonnull' if the pointer should never be null
    + (NSString *)getUserData;
                ^
                 _Nonnull
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/FBSDKAppEvents.h:714:44: warning: pointer is missing a nullability type specifier (_Nonnull, _Nullable, or _Null_unspecified) [-Wnullability-completeness]
    + (void)updateUserProperties:(NSDictionary *)properties handler:(FBSDKGraphRequestHandler)handler;
                                               ^
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/FBSDKAppEvents.h:714:44: note: insert '_Nullable' if the pointer may be null
    + (void)updateUserProperties:(NSDictionary *)properties handler:(FBSDKGraphRequestHandler)handler;
                                               ^
                                                _Nullable
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/FBSDKAppEvents.h:714:44: note: insert '_Nonnull' if the pointer should never be null
    + (void)updateUserProperties:(NSDictionary *)properties handler:(FBSDKGraphRequestHandler)handler;
                                               ^
                                                _Nonnull
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/FBSDKAppEvents.h:714:66: warning: block pointer is missing a nullability type specifier (_Nonnull, _Nullable, or _Null_unspecified) [-Wnullability-completeness]
    + (void)updateUserProperties:(NSDictionary *)properties handler:(FBSDKGraphRequestHandler)handler;
                                                                     ^
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/FBSDKAppEvents.h:714:66: note: insert '_Nullable' if the block pointer may be null
    + (void)updateUserProperties:(NSDictionary *)properties handler:(FBSDKGraphRequestHandler)handler;
                                                                     ^
                                                                                              _Nullable 
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/FBSDKAppEvents.h:714:66: note: insert '_Nonnull' if the block pointer should never be null
    + (void)updateUserProperties:(NSDictionary *)properties handler:(FBSDKGraphRequestHandler)handler;
                                                                     ^
                                                                                              _Nonnull 
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/FBSDKAppEvents.h:726:43: warning: pointer is missing a nullability type specifier (_Nonnull, _Nullable, or _Null_unspecified) [-Wnullability-completeness]
    + (void)augmentHybridWKWebView:(WKWebView *)webView;
                                              ^
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/FBSDKAppEvents.h:726:43: note: insert '_Nullable' if the pointer may be null
    + (void)augmentHybridWKWebView:(WKWebView *)webView;
                                              ^
                                               _Nullable
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/FBSDKAppEvents.h:726:43: note: insert '_Nonnull' if the pointer should never be null
    + (void)augmentHybridWKWebView:(WKWebView *)webView;
                                              ^
                                               _Nonnull
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/Internal/AppEvents/FBSDKPaymentObserver.m:242:38: error: property 'subscriptionPeriod' not found on object of type 'SKProduct *'
          BOOL isSubscription = (product.subscriptionPeriod != nil) && ((unsigned long)product.subscriptionPeriod.numberOfUnits > 0);
                                         ^
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/Internal/AppEvents/FBSDKPaymentObserver.m:242:92: error: property 'subscriptionPeriod' not found on object of type 'SKProduct *'
          BOOL isSubscription = (product.subscriptionPeriod != nil) && ((unsigned long)product.subscriptionPeriod.numberOfUnits > 0);
                                                                                               ^
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/Internal/AppEvents/FBSDKPaymentObserver.m:248:9: error: use of undeclared identifier 'SKProductSubscriptionPeriod'
            SKProductSubscriptionPeriod *period = product.subscriptionPeriod;
            ^
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/Internal/AppEvents/FBSDKPaymentObserver.m:248:38: error: use of undeclared identifier 'period'
            SKProductSubscriptionPeriod *period = product.subscriptionPeriod;
                                         ^
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/Internal/AppEvents/FBSDKPaymentObserver.m:248:55: error: property 'subscriptionPeriod' not found on object of type 'SKProduct *'
            SKProductSubscriptionPeriod *period = product.subscriptionPeriod;
                                                          ^
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/Internal/AppEvents/FBSDKPaymentObserver.m:250:17: error: use of undeclared identifier 'period'
            switch (period.unit) {
                    ^
    /Users/javier/Documents/Android_Studio_Projects/squat_app/ios/Pods/FBSDKCoreKit/FBSDKCoreKit/FBSDKCoreKit/Internal/AppEvents/FBSDKPaymentObserver.m:256:76: error: use of undeclared identifier 'period'
            NSString *p = [NSString stringWithFormat:@"P%lu%@", (unsigned long)period.numberOfUnits, unit];
                                                                               ^
    5 warnings and 7 errors generated.
Could not build the application for the simulator.
Error launching application on iPhone X.

I did flutter clean and pod update in the ios folder but keeps crashing. I don't know what's happening and if it's more a package problem than mine.

Here's the output of my flutter doctor -v

[✓] Flutter (Channel beta, v0.9.4, on Mac OS X 10.12.6 16G1036, locale en-ES)
    • Flutter version 0.9.4 at /Users/javier/Documents/flutter
    • Framework revision f37c235c32 (4 weeks ago), 2018-09-25 17:45:40 -0400
    • Engine revision 74625aed32
    • Dart version 2.1.0-dev.5.0.flutter-a2eb050044

[✓] Android toolchain - develop for Android devices (Android SDK 28.0.3)
    • Android SDK at /Users/javier/Library/Android/sdk
    • Android NDK location not configured (optional; useful for native profiling support)
    • Platform android-28, build-tools 28.0.3
    • 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-1136-b06)
    • All Android licenses accepted.

[✓] iOS toolchain - develop for iOS devices (Xcode 9.0)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 9.0, Build version 9A235
    • ios-deploy 1.9.2
    • CocoaPods version 1.5.3

[✓] Android Studio (version 3.2)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin version 29.1.1
    • Dart plugin version 181.5656
    • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1136-b06)

[✓] Connected devices (2 available)
    • Mi A1    • 1f95603a0804                         • android-arm64 • Android 8.1.0 (API 27)
    • iPhone X • 32CD2ECE-8C12-4F3A-B768-E1568B9754A7 • ios           • iOS 11.0 (simulator)

I'd appreciate if someone could help me finding the cause of this issue because I'm pretty lost right now.

Thanks in advance!

Solution

Looks like the problem was my Xcode version. I updated to 9.2 and now it works fine.

Here's my Doctor output

[✓] Flutter (Channel beta, v0.9.4, on Mac OS X 10.12.6 16G1036, locale en-ES)
    • Flutter version 0.9.4 at /Users/javier/Documents/flutter
    • Framework revision f37c235c32 (4 weeks ago), 2018-09-25 17:45:40 -0400
    • Engine revision 74625aed32
    • Dart version 2.1.0-dev.5.0.flutter-a2eb050044

[✓] Android toolchain - develop for Android devices (Android SDK 28.0.3)
    • Android SDK at /Users/javier/Library/Android/sdk
    • Android NDK location not configured (optional; useful for native profiling support)
    • Platform android-28, build-tools 28.0.3
    • 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-1136-b06)
    • All Android licenses accepted.

[✓] iOS toolchain - develop for iOS devices (Xcode 9.0)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 9.0, Build version 9A235
    • ios-deploy 1.9.2
    • CocoaPods version 1.5.3

[✓] Android Studio (version 3.2)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin version 29.1.1
    • Dart plugin version 181.5656
    • Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1136-b06)

[✓] Connected devices (2 available)
    • Mi A1    • 1f95603a0804                         • android-arm64 • Android 8.1.0 (API 27)
    • iPhone X • 32CD2ECE-8C12-4F3A-B768-E1568B9754A7 • ios           • iOS 11.0 (simulator)

• No issues found!