Unit Tests work correctly when running but not when debugging in Android Studio 4.1

Question

I upgraded android studio and I get this weird behaviour

when I run my unit tests they run and complete correctly (I introduced some errors to make sure it was so)

but when I put a breakpoint and use debug tests in java the jvm crashes with this error:

"C:\Program Files\Android\Android Studio4\jre\bin\java.exe" - agentlib:jdwp=transport=dt_socket,address=127.0.0.1:64493,suspend=y,server=n -ea -javaagent:C:\Users\imavrelos\.gradle\caches\modules-2\files-2.1\org.jetbrains.kotlinx\kotlinx-coroutines-core-jvm\1.3.9\4be434f5e86c1998a273e7f19a7286440894f0b0\kotlinx-coroutines-core-jvm-1.3.9.jar -Didea.test.cyclic.buffer.size=1048576 -javaagent:C:\Users\imavrelos\AppData\Local\Google\AndroidStudio4.1\groovyHotSwap\gragent.jar -javaagent:C:\Users\imavrelos\AppData\Local\Google\AndroidStudio4.1\captureAgent\debugger-agent.jar -Dfile.encoding=UTF-8 -classpath "C:\Program Files\Android\Android Studio4\lib\idea_rt.jar" com.intellij.rt.execution.CommandLineWrapper C:\Users\imavrelos\AppData\Local\Temp\idea_classpath1657759720 com.intellij.rt.junit.JUnitStarter -ideVersion5 @w@C:\Users\imavrelos\AppData\Local\Temp\idea_working_dirs_junit.tmp @C:\Users\imavrelos\AppData\Local\Temp\idea_junit.tmp -socket64492
Connected to the target VM, address: '127.0.0.1:64493', transport: 'socket'
java.lang.NoClassDefFoundError: kotlin/collections/AbstractMutableMap
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:757)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:468)
    at java.net.URLClassLoader.access$100(URLClassLoader.java:74)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:369)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:363)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:362)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:419)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:352)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:352)
    at kotlinx.coroutines.debug.internal.DebugProbesImpl.<clinit>(DebugProbesImpl.kt:30)
    at kotlinx.coroutines.debug.AgentPremain.<clinit>(AgentPremain.kt:26)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at sun.instrument.InstrumentationImpl.loadClassAndStartAgent(InstrumentationImpl.java:386)
    at sun.instrument.InstrumentationImpl.loadClassAndCallPremain(InstrumentationImpl.java:401)
Caused by: java.lang.ClassNotFoundException: kotlin.collections.AbstractMutableMap
    at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:419)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:352)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:352)
    ... 20 more
FATAL ERROR in native method: processing of -javaagent failed
Disconnected from the target VM, address: '127.0.0.1:64493', transport: 'socket'

Process finished with exit code 1
Exception in thread "main" 

has anyone got this error? any suggestions on how to fix it?

Answer 1

I fixed it by editing the current Run/Debug Configuration and choosing JAR Manifest in the Shorten command line option.

Answer 2

A similar error can also be caused by using kotlinx-coroutines-core, but it seems to depend on the IDEA version or library.

In my case, debug stopped working after updating IDEA Ultimate to version 2021.2

Answer 3

I fixed this error by editing the current Run/Debug Configuration and disabling the "Shorten command line" option. Before it was set to "classpath file" which seems to bring up the above error in some cases.

Answer 4

I wrote a unit test for a library. When running with usual Ctrl + Shift + F10 it executed, but when tried to debug the test, it didn't run with the error: 'Exception in thread "main" java.lang.NoClassDefFoundError: kotlin/collections/AbstractMutableMap'.

Then I moved the unit test to instrumentation test.