This is a copy of the template.

Copy of the template.

Do these mean this will break for consumers?

No, the original format of the Generated.xcconfig is the same, and this method isn't accessible outside this file (unless someone was doing some really weird hackery). The method return type is different now, but I changed the two places we call it.

Sorry, I mean the fact that you had to update all of these - will it not be automatic for people running Flutter on existing projects?

The only place this method is called is within this Podfile. So if they regenerate the Podfile they will get the updated method and the updated usage.

P.S. The stale framework issue this is fixing happens when developers fail to follow the deployment instructions and do not run flutter build ios in release before archiving. So if the Podfile isn't updated, but they follow instructions, they will be fine.

Maybe we could read the podfile an dlook for the the offending line?

A more detailed message, or a link to some docs on the website, could help folks do the necessary update manually if they have local edits they want to keep. Like, "Your Podfile is out of date. Regenerate it with .... If you have local edits that you'd like to keep, see ... for instructions."

It's easy to see if their Podfile is out of date without parsing (either .symlinks/flutter exists or it doesn't since that directory gets removed and recreated each pod install run).
The minimum Podfile change (without the mapping refactor) is pretty large, so it's not just a one-line swap:

generated_xcode_build_settings = parse_KV_file('./Flutter/Generated.xcconfig')
if generated_xcode_build_settings.empty?
  puts "Generated.xcconfig must exist. If you're running pod install manually, make sure flutter pub get is executed first."
end
generated_xcode_build_settings.map { |p|
  if p[:name] == 'FLUTTER_FRAMEWORK_DIR'
    symlink = File.join('.symlinks', 'flutter')
    File.symlink(File.dirname(p[:path]), symlink)
    pod 'Flutter', :path => File.join(symlink, File.basename(p[:path]))
  end
}

becomes:

copied_flutter_dir = File.join(__dir__, 'Flutter')
copied_framework_path = File.join(copied_flutter_dir, 'Flutter.framework')
copied_podspec_path = File.join(copied_flutter_dir, 'Flutter.podspec')
unless File.exist?(copied_framework_path) && File.exist?(copied_podspec_path)
  generated_xcode_build_settings = parse_KV_file('./Flutter/Generated.xcconfig')
  if generated_xcode_build_settings.empty?
    puts "Generated.xcconfig must exist. If you're running pod install manually, make sure flutter pub get is executed first."
  end
  generated_xcode_build_settings = parse_KV_file(generated_xcode_build_settings_path)
  generated_xcode_build_settings.map { |p|
    if p[:name] == 'FLUTTER_FRAMEWORK_DIR'
      cached_framework_dir = p[:path]
      unless File.exist?(copied_framework_path)
        FileUtils.cp_r(File.join(cached_framework_dir, 'Flutter.framework'), copied_flutter_dir)
      end
      unless File.exist?(copied_podspec_path)
        FileUtils.cp(File.join(cached_framework_dir, 'Flutter.podspec'), copied_flutter_dir)
      end
    end
  }
end

pod 'Flutter', :path => 'Flutter'

Here's what it looks like when I have an old version, build, get the migration instructions, remove the Podfile, then build again:

Note I need to actually add instructions to that issue.

Copy of the template.