The depot_tools Ninja wrapper looks for Ninja at specific paths within the tree. The use of "name": "." in the engine's .gclient file is not expected by the depot_tools logic for locating the engine's source directory. This PR creates an alternative layout that is supported by depot_tools. If the project root directory contains a "buildtools" subdirectory, then depot_tools will look for Ninja at "third_party/ninja" within the root. Fixes https://github.com/flutter/flutter/issues/163487
Flutter Engine
Setting up the Engine development environment
See here
gclient bootstrap
Flutter engine uses gclient to manage dependencies.
If you've already cloned the flutter repository: