fix: Issue with Black Screen on iOS After Hotfix Update Using Different Shorebird Versions

[JedTsai33]

App ID: 0201f7bd-11de-4ad3-af2b-d8b317cb1c33

Description

We are using GitHub to package the .ipa file and installing Shorebird via shorebirdtech/setup-shorebird@v1.

Previously, we released a version using Shorebird v1.4.1. Today, we attempted to publish a patch update using Shorebird v1.4.15. However, after the hotfix was applied, opening the app resulted in a black screen.

Through further testing, we found that:

If both the release and the patch are built with Shorebird v1.4.15, the hotfix works correctly without any issues.

Questions:

1. Why does updating to a newer version of Shorebird cause the iOS app to display a black screen after a hotfix?
2. Is it possible to let users control the Shorebird version during installation to avoid similar issues in the future?

[eseidel]

I don't believe this has anything to do with the Shorebird version. (It's possible, but unlikely.) Shorebird always uses the exact Flutter matching the release when building a patch, regardless of Shorebird version.

But it does look like 7.100.5+710005 patch 5, had native changes, which easily could explain a black screen:

  "has_asset_changes": true,
  "has_native_changes": true,
  "release_platform": "ios",
  "used_ignore_asset_changes_flag": true,
  "used_ignore_native_changes_flag": true

I'd strongly recommend not ignoring native changes.
https://docs.shorebird.dev/troubleshooting/#i-see-a-your-app-contains-native-changes-warning-when-running-shorebird-patch-even-though-i-havent-changed-swiftobjective-ckotlinjava-code

The way that Shorebird works is that it replaces all the Dart code in your app. It does not change any of the "native" code (Obj-C/Swift/Kotlin/Dart/C++, etc.), so if you have changed native code and patch, you will end up running new Dart code with old "native" code, and thus can end up in a confused state. shorebird warns if this happens, but it looks like when these patches were made those warnings were overridden.

I've filed #2669 for displaying a warning about this in the console.

[eseidel]

Can you share the command you used to build the patch?