Debug flags

In most cases, you won’t need to use the debug flags
directly, as you’ll find the most useful debugging
functionality in the DevTools suite. But if you
prefer to use the debug flags directly, see
Debug flags: performance in the
Debugging Flutter apps programmatically page.

Common problems

The following is a problem that some have encountered on MacOS.

“Too many open files” exception (MacOS)

The default limit for Mac OS on how many files it can have open at a
time is rather low.  If you run into this limit,
increase the number of available
file handlers using the ulimit command:

If you use Travis or Cirrus for testing, increase the number of
available file handlers that they can open by adding the same line to
flutter/.travis.yml, or flutter/.cirrus.yml, respectively.

Widgets marked const that should be equal to each other, aren’t