
It turns out that when a PR build clones the flutter repo, it puts it into a directory called "flutter", and when the "real" build clones the flutter repo, it puts it into a directory called "build". This allowed the tests to succeed in my PR, but fail when I committed it. This fixes the test so it doesn't depend on the cloned directory name.
Flutter tools
Tools for building Flutter applications.
To run the tests, ensure that no devices are connected,
then navigate to flutter_tools
and execute:
DART_VM_OPTIONS=--assert-initializer ../../bin/cache/dart-sdk/bin/pub run test