Non-sensical Error: Misplaced argument matcher detected here. You cannot use argument matchers outside of verification or stubbing in Mockito - unit-testing

Question

I have multiple Spock Test Suites in my code. When I try to execute them serially, I am getting the following error message on running Spock Tests:
Misplaced or misused argument matcher detected here:
[junit]
[junit] -> at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
[junit]
[junit] You cannot use argument matchers outside of verification or stubbing.
[junit] Examples of correct usage of argument matchers:
[junit] when(mock.get(anyInt())).thenReturn(null);
[junit] doThrow(new RuntimeException()).when(mock).someVoidMethod(anyObject());
[junit] verify(mock).someMethod(contains("foo"))
[junit]
[junit] This message may appear after an NullPointerException if the last matcher is returning an object
[junit] like any() but the stubbed method signature expect a primitive argument, in this case,
[junit] use primitive alternatives.
[junit] when(mock.get(any())); // bad use, will raise NPE
[junit] when(mock.get(anyInt())); // correct usage use
[junit]
[junit] Also, this error might show up because you use argument matchers with methods that cannot be mocked.
[junit] Following methods *cannot* be stubbed/verified: final/private/equals()/hashCode().
[junit] Mocking methods declared on non-public parent classes is not supported.
[junit]
[junit] org.mockito.exceptions.misusing.InvalidUseOfMatchersException:
[junit] Misplaced or misused argument matcher detected here:
[junit]
[junit] -> at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:48)
[junit]
[junit] You cannot use argument matchers outside of verification or stubbing.
[junit] Examples of correct usage of argument matchers:
[junit] when(mock.get(anyInt())).thenReturn(null);
[junit] doThrow(new RuntimeException()).when(mock).someVoidMethod(anyObject());
[junit] verify(mock).someMethod(contains("foo"))
[junit]
[junit] This message may appear after an NullPointerException if the last matcher is returning an object
[junit] like any() but the stubbed method signature expect a primitive argument, in this case,
[junit] use primitive alternatives.
[junit] when(mock.get(any())); // bad use, will raise NPE
[junit] when(mock.get(anyInt())); // correct usage use
[junit]
[junit] Also, this error might show up because you use argument matchers with methods that cannot be mocked.
[junit] Following methods *cannot* be stubbed/verified: final/private/equals()/hashCode().
[junit] Mocking methods declared on non-public parent classes is not supported.
[junit]
[junit] at com.example.app.MySecondTest.test update usages(MySecondTest.groovy:19)
[junit]
However, the error points to MySecondTest.groovy:19 which in my case contains the following code
ExampleService exampleService = Mockito.mock(ExampleService.class)
There is no use of Argument Matcher in MySecondTest. But still I am getting this error.
Curiously, if I run only this test, I do not get any error and the test runs successfully

Answer 1

It turns out the error message points to next TestSuite that is executed after the test that actually contains a misplaced Argument Matcher.
In my case, the test suite MyFirstTest, which was executed before the test suite MySecondTest contained a test method that had a misplaced Argument Matcher.