State of Catalina Support

Members of the Flutter team are working to bring full macOS Catalina support to Flutter. In the mean time, we know that some of you have wanted to use the macOS Catalina betas with Flutter. Here’s christopherfujino’s step-by-step diary of what he’s experienced getting it working, which is helping inform the team’s work as to what’s necessary.

OS Setup

1. This was on a new Mac Mini, right from the Apple Store
2. Upgraded OS to Catalina preview, via https://www.apple.com/macos/catalina-preview/
3. Used a Googler dev account.
4. On macOS Catalina v10.15 Beta (19A512f), XCode Beta 11.0
5. On iterm2

Journal

1. Downloaded stable flutter sdk from flutter.dev, v1.7.8+hotfix.3
2. OS X prompts if iterm2 should be allowed access to “$HOME/Downloads”(?!)
3. When I enter the command “flutter/bin/flutter doctor”, OS X says “dart” can’t be opened because it was not downloaded from the App Store
   1. After going to Settings -> Security & Privacy -> Open Anyway, I get another dialog: “dart” is a Unix app downloaded from the Internet. Are you sure you want to open it?
   2. On clicking “open”, a new “Terminal” window was opened, and then it executes just “dart”, without any arguments, and then the terminal session exits.
4. When I re-issue the same command, “flutter/bin/flutter doctor”, this time the actual flutter tool is run, however a new dialog is opened: “kernel-service.dart.snapshot” can’t be opened because Apple cannot check it for malicious software. 3. When I go to Settings -> Security & Privacy -> Open Anyway, nothing happens. The text next to the button says: kernel-service.dart.snapshot was blocked from opening because it is not from an identified developer. Re-running the command results in no change.
5. Trying to switch channels failed with:

flutter@macN1 flutter % bin/flutter channel master
Switching to flutter channel 'master'...
../../third_party/dart/runtime/bin/snapshot_utils.cc: 149: error: Failed to memory map snapshot: /Users/flutter/flutter/bin/cache/dart-sdk/bin/snapshots/kernel-service.dart.snapshot version=2.4.0 (Wed Jun 19 11:53:45 2019 +0200) on "macos_x64"
thread=5891, isolate=(null)(0x0)
 pc 0x000000010bd945d5 fp 0x0000700006ee7c40 dart::Profiler::DumpStackTrace(void*)
 pc 0x000000010badfdc2 fp 0x0000700006ee7d20 dart::Assert::Fail(char const*, ...)
 pc 0x000000010bac2dfb fp 0x0000700006ee7dd0 dart::bin::Snapshot::TryReadAppSnapshot(char const*)
 pc 0x000000010bac7eea fp 0x0000700006ee7e50 dart::bin::CreateIsolateAndSetup(char const*, char const*, char const*, char const*, Dart_IsolateFlags*, void*, char**)
 pc 0x000000010bcdba48 fp 0x0000700006ee7f00 dart::RunKernelTask::Run()
 pc 0x000000010be36a0d fp 0x0000700006ee7f30 dart::ThreadPool::Worker::Loop()
 pc 0x000000010be36880 fp 0x0000700006ee7f70 dart::ThreadPool::Worker::Main(unsigned long)
 pc 0x000000010bd90fc1 fp 0x0000700006ee7fb0 dart::ThreadStart(void*)
 pc 0x00007fff73470cce fp 0x0000700006ee7fd0 _pthread_start
 pc 0x00007fff7346d72b fp 0x0000700006ee7ff0 thread_start
-- End of DumpStackTrace
bin/flutter: line 183:  8210 Abort trap: 6           "$DART" --packages="$FLUTTER_TOOLS_DIR/.packages" $FLUTTER_TOOL_ARGS "$SNAPSHOT_PATH" "$@"

6. Following this article and this comment, I disabled Gatekeeper globally, so that binaries can execute without being signed. Now flutter doctor no longer throws the dialog about “kernel-service.dart.snapshot” being unsigned. I was also able to successfully switch channels to master. Issue
7. Under “flutter doctor” (FlutterValidator), “Downloaded executables cannot execute on host”. Issue
8. We will have to update website documentation on updating path to reflect that Catalina will default to zsh. I updated my path in $HOME/.zshrc. Issue
9. I don’t know how to install xcode. Tried the app store, I’m getting weird hits, including tutorials and xcode plugins, but I don’t see an actual xcode install...so it turns out the App Store version of Xcode doesn’t support Catalina. I needed to install the beta version from https://developer.apple.com/download
10. Even after installing the Xcode beta, flutter doctor can’t detect it. The instructions “sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer” don’t work because xcode isn’t at that location. Fixed: .app file was in $HOME/Downloads/
11. Cocoapods not detected, looks like this issue. Fixed with “sudo gem install -n /usr/local/bin cocoapods”. Ran “pod setup” and cocoapods support detected. Issue
12. With ios 13 simulator, issued “flutter run”, it worked.
13. Attempted to run on ipod touch in debug:
    1. No valid code signing certs
    2. Following instructions, “open ios/Runner.xcworkspace” -> Xcode
    3. In Xcode 11.0 beta 4, the signing interface is no longer under “General”, but in its own category, “Signing & Capabilities” Issue
    4. Re-running “flutter run”, hit this issue, however it doesn’t seem Catalina-dependent. “Flutter clean” fixed it.
14. It seems like for each new Flutter app to be run on an iOS device, the cert needs to be added in Xcode. Issue
15. Attempted to run on ipod touch in release:
    1. Successful
16. Downloaded Android Studio/SDK
    1. Intel HAXM installer was blocked by Gatekeeper
    2. “Flutter run” successful on emulator
17. Attempting to run on LG G7 ThinQ in debug:
    1. Successful
18. Attempting to run on LG G7 ThinQ in release:
    1. Successful
19. Run devicelab integration_ui_ios.dart test, passes
20. Build APK
    1. Failure Issue

Issues

1. Gatekeeper preventing “kernel-service.dart.snapshot” from executing #36714
2. [Xcode] Cannot build 32-bit APK on XCode >= 10 flutter #36114 Dart #36839
3. Website will need to updated to illustrate how to update path for zsh (Catalina’s default shell)
4. [Xcode] Cocoapod path broken by upgrading system ruby version #36786
5. [Xcode] Maybe update website documentation to reflect new location in Xcode of how to configure signing certificate
6. [Xcode] For each flutter app that I tried to run on an iOS device, I had to add my signing certificate in XCode.

Links

1. Official Apple Preview Website
2. All Github Catalina Issues
3. Article on security changes
4. Analytics on "run" usage of Catalina users vs total