While taking a look at #539 I noticed that SoftAssertions#fail(String failureMessage, Throwable realCause) could be more useful, at the moment it does not show any information about realCause.

@Test
public void test() {
    softly.fail("failure", new RuntimeException("abc"));
    softly.assertAll();
}

just displays:

org.assertj.core.api.SoftAssertionError:
The following assertion failed:

1. failure

   at org.assertj.core.api.SoftAssertions.assertAll(SoftAssertions.java:116)
   at org.assertj.core.api.SoftAssertionsTest.test(SoftAssertionsTest.java:115)

The error message etc. of realCause is lost.