Issue 1:
Steps to Reproduce

Make a change in the project's AppDelegate.m that results in a compiler warning. e.g. mark the AppDelegate class as +__attribute__((deprecated("foo"))) in AppDelegate.h

flutter build ios

The compiler warnings should be emitted to the stderr, but today are not displayed.

Issue 2:
Steps to Reproduce

Create an app using Firestore (cloud_firestore in dependencies). For example, the official Firebase for Flutter codelab.

Neglect to set up the iOS project with GoogleService-Info.plist.

flutter run the app on iOS.

Logs

This is what flutter run shows, in its entirety:

Launching lib/main.dart on iPhone X in debug mode...
*** First throw call stack:
(
0 CoreFoundation 0x000000010930d29b __exceptionPreprocess + 331
1 libobjc.A.dylib 0x00000001088a9735 objc_exception_throw + 48
2 CoreFoundation 0x000000010930d0f5 +[NSException raise:format:] + 197
3 Runner 0x0000000104947aa1 +[FIRApp configure] + 481
4 Runner 0x0000000104c9d22c -[FLTCloudFirestorePlugin init] + 188
5 Runner 0x0000000104c9d0d9 +[FLTCloudFirestorePlugin registerWithRegistrar:] + 297
6 Runner 0x00000001048f06bb +[GeneratedPluginRegistrant registerWithRegistry:] + 123
7 Runner <…>
Starting Xcode build...
Xcode build done.
*** First throw call stack:
(
0 CoreFoundation 0x000000010665829b __exceptionPreprocess + 331
1 libobjc.A.dylib 0x0000000105bf4735 objc_exception_throw + 48
2 CoreFoundation 0x00000001066580f5 +[NSException raise:format:] + 197
3 Runner 0x0000000101befaa1 +[FIRApp configure] + 481
4 Runner 0x0000000101f4522c -[FLTCloudFirestorePlugin init] + 188
5 Runner 0x0000000101f450d9 +[FLTCloudFirestorePlugin registerWithRegistrar:] + 297
6 Runner 0x0000000101b986bb +[GeneratedPluginRegistrant registerWithRegistry:] + 123
7 Runner <…>

Here's what you get in Xcode:

2018-10-01 16:30:54.093692-0700 Runner[21990:12461249] - <AppMeasurement>[I-ACS036002] Analytics screen reporting is enabled. Call +[FIRAnalytics setScreenName:setScreenClass:] to set the screen name or override the default screen class name. To disable screen reporting, set the flag FirebaseScreenReportingEnabled to NO (boolean) in the Info.plist
2018-10-01 16:30:54.370913-0700 Runner[21990:12460659] You've implemented -[<UIApplicationDelegate> application:performFetchWithCompletionHandler:], but you still need to add "fetch" to the list of your supported UIBackgroundModes in your Info.plist.
2018-10-01 16:30:54.371112-0700 Runner[21990:12460659] You've implemented -[<UIApplicationDelegate> application:didReceiveRemoteNotification:fetchCompletionHandler:], but you still need to add "remote-notification" to the list of your supported UIBackgroundModes in your Info.plist.
2018-10-01 16:30:54.385564-0700 Runner[21990:12460659] *** Terminating app due to uncaught exception 'com.firebase.core', reason: '`[FIRApp configure];` (`FirebaseApp.configure()` in Swift) could not find a valid GoogleService-Info.plist in your project. Please download one from https://console.firebase.google.com/.'
*** First throw call stack:
(
0 CoreFoundation 0x000000010ac0529b __exceptionPreprocess + 331
1 libobjc.A.dylib 0x000000010a1a1735 objc_exception_throw + 48
2 CoreFoundation 0x000000010ac050f5 +[NSException raise:format:] + 197
3 Runner 0x0000000105fe9aa1 +[FIRApp configure] + 481
4 Runner 0x000000010633f22c -[FLTCloudFirestorePlugin init] + 188
5 Runner 0x000000010633f0d9 +[FLTCloudFirestorePlugin registerWithRegistrar:] + 297
6 Runner 0x0000000105f926bb +[GeneratedPluginRegistrant registerWithRegistry:] + 123
7 Runner 0x0000000105f927ca $S6Runner11AppDelegateC11application_29didFinishLaunchingWithOptionsSbSo13UIApplicationC_SDySo0j6LaunchI3KeyaypGSgtF + 138
8 Runner 0x0000000105f92bb4 $S6Runner11AppDelegateC11application_29didFinishLaunchingWithOptionsSbSo13UIApplicationC_SDySo0j6LaunchI3KeyaypGSgtFTo + 228
9 UIKitCore 0x00000001133ac4d7 -[UIApplication _handleDelegateCallbacksWithOptions:isSuspended:restoreState:] + 280
10 UIKitCore 0x00000001133adec4 -[UIApplication _callInitializationDelegatesForMainScene:transitionContext:] + 3979
11 UIKitCore 0x00000001133b3527 -[UIApplication _runWithMainScene:transitionContext:completion:] + 1623
12 UIKitCore 0x0000000113c55e3e __111-[__UICanvasLifecycleMonitor_Compatability _scheduleFirstCommitForScene:transition:firstActivation:completion:]_block_invoke + 866
13 UIKitCore 0x0000000113c52403 +[_UICanvas _enqueuePostSettingUpdateTransactionBlock:] + 153
14 UIKitCore 0x0000000113c55a7b -[__UICanvasLifecycleMonitor_Compatability _scheduleFirstCommitForScene:transition:firstActivation:completion:] + 233
15 UIKitCore 0x0000000113c56435 -[__UICanvasLifecycleMonitor_Compatability activateEventsOnly:withContext:completion:] + 1085
16 UIKitCore 0x0000000113c13b31 __82-[_UIApplicationCanvas _transitionLifecycleStateWithTransitionContext:completion:]_block_invoke + 795
17 UIKitCore 0x0000000113c137db -[_UIApplicationCanvas _transitionLifecycleStateWithTransitionContext:completion:] + 435
18 UIKitCore 0x0000000113c5892c __125-[_UICanvasLifecycleSettingsDiffAction performActionsForCanvas:withUpdatedScene:settingsDiff:fromSettings:transitionContext:]_block_invoke + 584
19 UIKitCore 0x0000000113c59256 _performActionsWithDelayForTransitionContext + 100
20 UIKitCore 0x0000000113c5868b -[_UICanvasLifecycleSettingsDiffAction performActionsForCanvas:withUpdatedScene:settingsDiff:fromSettings:transitionContext:] + 221
21 UIKitCore 0x0000000113c51aa1 -[_UICanvas scene:didUpdateWithDiff:transitionContext:completion:] + 392
22 UIKitCore 0x00000001133b1d46 -[UIApplication workspace:didCreateScene:withTransitionContext:completion:] + 515
23 UIKitCore 0x00000001133e3856 -[UIApplicationSceneClientAgent scene:didInitializeWithEvent:completion:] + 357
24 FrontBoardServices 0x00000001166aedda -[FBSSceneImpl _didCreateWithTransitionContext:completion:] + 448
25 FrontBoardServices 0x00000001166b9f43 __56-[FBSWorkspace client:handleCreateScene:withCompletion:]_block_invoke_2 + 271
26 FrontBoardServices 0x00000001166b963a __40-[FBSWorkspace _performDelegateCallOut:]_block_invoke + 53
27 libdispatch.dylib 0x000000010c64e63e _dispatch_client_callout + 8
28 libdispatch.dylib 0x000000010c651bb4 _dispatch_block_invoke_direct + 301
29 FrontBoardServices 0x00000001166ee3c8 __FBSSERIALQUEUE_IS_CALLING_OUT_TO_A_BLOCK__ + 30
30 FrontBoardServices 0x00000001166ee080 -[FBSSerialQueue _performNext] + 457
31 FrontBoardServices 0x00000001166ee660 -[FBSSerialQueue _performNextFromRunLoopSource] + 45
32 CoreFoundation 0x000000010ab68b31 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
33 CoreFoundation 0x000000010ab683a3 __CFRunLoopDoSources0 + 243
34 CoreFoundation 0x000000010ab62a4f __CFRunLoopRun + 1263
35 CoreFoundation 0x000000010ab62221 CFRunLoopRunSpecific + 625
36 GraphicsServices 0x000000010fcd01dd GSEventRunModal + 62
37 UIKitCore 0x00000001133b5115 UIApplicationMain + 140
38 Runner 0x0000000105f92d84 main + 68
39 libdyld.dylib 0x000000010c6c4551 start + 1
)
2018-10-01 16:30:54.489749-0700 Runner[21990:12461272] flutter: Observatory listening on http://127.0.0.1:49397/
libc++abi.dylib: terminating with uncaught exception of type NSException
2018-10-01 16:30:54.404948-0700 Runner[21990:12461249] 5.6.0 - [Firebase/Core][I-COR000003] The default Firebase app has not yet been configured. Add `[FIRApp configure];` (`FirebaseApp.configure()` in Swift) to your application initialization. Read more: https://goo.gl/ctyzm8.

Note the helpful error that is only visible in Xcode:

could not find a valid GoogleService-Info.plist in your project. Please download one from https://console.firebase.google.com/

Flutter doctor

$ flutter doctor -v
[✓] Flutter (Channel beta, v0.8.2, on Mac OS X 10.13.6 17G65, locale en-US)
• Flutter version 0.8.2 at /Users/filiph/dev/flutter
• Framework revision 5ab9e70727 (3 weeks ago), 2018-09-07 12:33:05 -0700
• Engine revision 58a1894a1c
• Dart version 2.1.0-dev.3.1.flutter-760a9690c2

[✓] Android toolchain - develop for Android devices (Android SDK 27.0.3)
• Android SDK at /Users/filiph/Library/Android/sdk
• Android NDK location not configured (optional; useful for native profiling support)
• Platform android-27, build-tools 27.0.3
• 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 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 (version 3.2)
• Android Studio at /Applications/Android Studio.app/Contents
• Flutter plugin version 28.0.2
• Dart plugin version 181.5616
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1136-b06)

[!] IntelliJ IDEA Community Edition (version 2018.1)
• IntelliJ at /Applications/IntelliJ IDEA CE.app
✗ 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 1.22.2)
• VS Code at /Applications/Visual Studio Code.app/Contents
• Flutter extension not installed; install from
https://marketplace.visualstudio.com/items?itemName=Dart-Code.flutter

[✓] Connected devices (3 available)
• Pixel 2 XL • 711KPZK0592485 • android-arm64 • Android 9 (API 28)
• iPhone X • A4DBE660-4C39-4AEA-B258-7755F584BA6E • ios • iOS 12.0 (simulator)
• iPhone XR • 431DF6F4-BF91-4E1D-9AF1-8324CF683D37 • ios • iOS 12.0 (simulator)

! Doctor found issues in 2 categories.