How to run dart fix across a whole repo to apply Flutter breaking-change migrations
dart fix takes one target directory and it can be the repo root: the analyzer opens a context per nested pubspec.yaml and migrates every package in one pass. Here is the full flag surface, the four things that silently suppress fixes and make a dirty repo report Nothing to fix, why the exit code is useless in CI, and a case where a Flutter transform emits code that does not compile.