Android Studio hangs / Freezes when project build fails

Question

I am experiencing a very wired problem since this evening.

If I have any errors in my android project, and build is failed, then my Android studio gets frozen / stuck. I

Answer 1

Based on barbarian's answer I did this on my Mac:

start a terminal
chmod +x gradlew
./gradlew
./gradlew build

This last step showed an error in my xml file, indicating that I used unescaped single quotes. Fixing that solved the hangup.