gradle - Android Studio: Where is the Compiler Error Output Window?

Question

When I 'Run' my project in Android Studio, in the 'Messages' window, I get:

Gradle: 
FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':play01:compileDebug'.
> Compilation failed; see the compiler error output for details.

* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

It says > Compilation failed; see the compiler error output for details. So where is the "compiler error output"? And/Or how do I run with --stacktrace option?

Answer 1

For Android Studio 3.1, select the icon below the Build one in the Build window.

By Android Studio 3.3 (possibly in 3.2.1), the icon has changed, though the location is the same:

The build window should open when you run a build action (e.g. from the Build menu). If you don't see it, you can try the "Build" button along the bottom of the window (also visible in the above screenshots), or through the menus View → Tool Windows → Build.