Sometimes Android Studio's Instant Run feature gets stuck

Today I helped one user who was seeing their Android Studio builds fail with a spew of exceptions mentioning InstantRunTransform in a few of the stack traces. This seems to belong to Android Studio's Instant Run feature, which allows deploying changes to the device without completely recompiling everything. This feature, though very nice, sometimes wedges itself into bad states. To disable it and force a full rebuild, you can disable it in the Build, Execution, Deployment | Instant Run settings section.