How to debug when running Robolectric tests in Android Studio?

Question

I need to run debug while running my tests in Android Studio + Robolectric. Every time I try to run them by selecting debug for the test task from Gradle tasks, I get an error message:

Error starting package_name: app_name [test]: cannot open the debugger port: java.net.SocketException "Socket closed"

Any ideas?

Answer 1

I found the cause of the error. To run it, you need to uncheck the "Use built-in assembly" in the settings of the Compiler → Gradle in Android Studio.

Answer 2

I was getting this error on Linux, and the problem was that another previous process took the port and hung it. Thus, the solution is netstat to find a process blocking a port, then kill that process or restart the computer.