Shorebird build failing due to invalid Flutter version string when fvm is configured

[lukemmtt]

If you are looking for help, please confirm the following...

• I confirm I have searched the Docs, Codemagic Sample Projects, and GitHub Discussions.
• I confirm the software versions on my local computer match the ones in CI environment (e.g. Xcode version, Gradle version). See here
• I confirm I am able to do a fresh clone of the repository and build the project on my local computer.

Which mobile framework are you using?

Flutter (Dart)

Steps to reproduce

1. Configure a Flutter iOS release build in Codemagic's Workflow editor, and configure it to build as a shorebird release.
2. In the Shorebird (build) step, for the Flutter Version, leave it at the default value of "Shorebird default".
3. Run the workflow.

Expected results

The build should complete successfully, using the latest Flutter version (3.29.2), which is what the Shorebird CLI does in my local Mac environment.

Actual results

The build fails, with the following output:

shorebird release ios --flutter-version '<class '"'"'utils.dict_to_object.new'"'"'>' --export-options-plist /Users/builder/export_options.plist --build-number=1727

Build failed :|
Failed to build for iOS

It is clear that an invalid argument, <class '"'"'utils.dict_to_object.new'"'"'>, is being passed to the --flutter-version parameter.

I use fvm, and I speculate that system is trying to pass my fvm flutter version to the shorebird command (instead of actually using the 'shorebird default', as it claims), resulting in a malformed command.

Here is what my "Shorebird" step looks like in the workflow editor:

This issue, in conjunction with this related issue (https://github.com/orgs/codemagic-ci-cd/discussions/3042) is making this process rather frustrating.

Build id (optional)

67e2ec19cf13025952046088

[dam-ease]

Hello @lukemmtt,
Thanks for the report!
We were able to reproduce the issue, but we found that it occurred due to a configuration issue in the Shorebird build settings switching in the Codemagic UI, and we are working to improve this.

Here is a workaround to resolve this on your end, pending the fix:

• In the Workflow Editor, navigate to the Shorebird build settings.
• Temporarily change the Flutter version to any other option (e.g., 3.27.3).
• Switch it back to "Shorebird default".
• Save the changes and rerun the build.

This should remove the --flutter-version=fvm argument and allow the build to complete successfully.

Screen.Recording.2025-03-26.at.09.24.48.mov

[lukemmtt]

Great! Thanks so much for the quick attention to this and for the workaround!