Issue 1:
Flutter crash report; please file at https://github.com/flutter/flutter/issues.

command

flutter build bundle --suppress-analytics --target /Users/jingjinggu/develope/longzhu/flutter/LongzhuFlutterAndroid/longzhuflutter/lib/main.dart --preview-dart-2 --target-platform android-arm64 --depfile /Users/jingjinggu/develope/longzhu/flutter/LongzhuFlutterAndroid/longzhuflutter/.android/Flutter/build/intermediates/flutter/debug/snapshot_blob.bin.d --asset-dir /Users/jingjinggu/develope/longzhu/flutter/LongzhuFlutterAndroid/longzhuflutter/.android/Flutter/build/intermediates/flutter/debug/flutter_assets --debug

exception

FileSystemException: FileSystemException: Cannot open file, path = 'build/app.dill' (OS Error: No such file or directory, errno = 2)

#0 _File.open.<anonymous closure> (dart:io/file_impl.dart:368:9)
#1 _rootRunUnary (dart:async/zone.dart:1132:38)
#2 _CustomZone.runUnary (dart:async/zone.dart:1029:19)
#3 _FutureListener.handleValue (dart:async/future_impl.dart:129:18)
#4 Future._propagateToListeners.handleValueCallback (dart:async/future_impl.dart:642:45)
#5 Future._propagateToListeners (dart:async/future_impl.dart:671:32)
#6 Future._completeWithValue (dart:async/future_impl.dart:486:5)
#7 Future._asyncComplete.<anonymous closure> (dart:async/future_impl.dart:516:7)
#8 _rootRun (dart:async/zone.dart:1124:13)
#9 _CustomZone.run (dart:async/zone.dart:1021:19)
#10 _CustomZone.bindCallback.<anonymous closure> (dart:async/zone.dart:947:23)
#11 _microtaskLoop (dart:async/schedule_microtask.dart:41:21)
#12 _startMicrotaskLoop (dart:async/schedule_microtask.dart:50:5)
#13 _runPendingImmediateCallback (dart:isolate/runtime/libisolate_patch.dart:114:13)
#14 _RawReceivePortImpl._handleMessage (dart:isolate/runtime/libisolate_patch.dart:170:5)

flutter doctor

[✓] Flutter (Channel master, v0.5.9-pre.30, on Mac OS X 10.13.5 17F77, locale zh-Hans-CN)
• Flutter version 0.5.9-pre.30 at /Users/jingjinggu/develope/flutter/flutter
• Framework revision 33c4cd0f39 (20 hours ago), 2018-08-13 23:43:49 -0700
• Engine revision e54bc4ea18
• Dart version 2.0.0-dev.69.5.flutter-eab492385c

[✓] Android toolchain - develop for Android devices (Android SDK 28.0.0)
• Android SDK at /Users/jingjinggu/Library/Android/sdk
• Android NDK at /Users/jingjinggu/Library/Android/sdk/ndk-bundle
• Platform android-28, build-tools 28.0.0
• ANDROID_HOME = /Users/jingjinggu/Library/Android/sdk
• Java binary at: /Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/bin/java
• Java version Java(TM) SE Runtime Environment (build 1.8.0_121-b13)
• All Android licenses accepted.

[✓] iOS toolchain - develop for iOS devices (Xcode 9.4)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Xcode 9.4, Build version 9F1027a
• ios-deploy 1.9.2
• CocoaPods version 1.5.3

[✗] Android Studio (not installed)
• Android Studio not found; download from https://developer.android.com/studio/index.html
(or visit https://flutter.io/setup/#android-setup for detailed instructions).

[!] VS Code (version 1.26.0)
• 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 (1 available)
• HUAWEI NXT AL10 • 5LM0216122011219 • android-arm64 • Android 7.0 (API 24)

! Doctor found issues in 2 categories.

Issue 2:
I've read through #4959 and am glad that a solution to specifying custom routeTransitions is available,

though I really wish there were predefined route transitions (like we have for Alignment.topLeft, or for mainAxisAlignment and other stuff), which we could call like:

Navigator.push(
context,
Transitions.SlideRight(screen: Screen(screenArgs))
);

this would reduce a lot of code duplication, at least one variant for each developer needing this, and considering that there are several transitions that are popular like, slides and fades, I fell this is not an unusual request.

Thanks for your time