This yak shave went as follows:
Fix https://github.com/flutter/flutter/issues/8795 by adding stocks to
the examples README.
Notice the layers entry in that README isn't quite right either.
Update that.
Check the layers/README file is worth pointing at.
Update the layers/README.
Let's run some of the layer tests to see if they still work.
Oops, need to update them to gradle.
Ok let's try running them again.
Oops, sector is broken.
Add a test for sector.
Fix sector. Find you need to add an assert to a const constructor.
Notice we need to turn const asserts on for the analyzer.
Notice the analysis_options files are out of sync with each other and
with the full list of lints.
Turn on the lints that should be on.
Fix the bugs that finds.
* Remove the workaround that pinned args to v0.13.6
This reverts most of the changes in commit 6331b6c8b5
* throw exception if exit code is not an integer
* rework command infrastructure to throw ToolExit when non-zero exitCode
* convert commands to return Future<Null>
* cleanup remaining commands to use throwToolExit for non-zero exit code
* remove isUnusual exception message
* add type annotations for updated args package
Switch our pubspec.yamls to using SDK sources so that we can have consistent
source types when we depend on these packages from external packages using SDK
sources.
...by adding tests to our examples that don't import flutter_test, which
pins the relevant dependencies.
Also, provide more information when complaining about leaked transient
callbacks in tests.
Also, make tests display full information when they have an exception,
by bypassing the throttling we have for Android logging in tests.
Also, make the word wrapping not wrap stack traces if they happen to
be included in exception output.
Also, fix a leaked transient callback in the checkbox code.
