Make FailException extend AssertionError, fixes #215

munit/shared/src/main/scala/munit/FailException.scala

@@ -5,7 +5,7 @@ class FailException(
     val cause: Throwable,
     val isStackTracesEnabled: Boolean,
     val location: Location
-) extends Exception(message, cause)
+) extends AssertionError(message, cause)
     with Serializable {
   def this(message: String, location: Location) =
     this(message, null, true, location)

tests/shared/src/test/scala/munit/FailExceptionSuite.scala

@@ -0,0 +1,7 @@
+package munit
+
+class FailExceptionSuite extends BaseSuite {
+  test("assertion-error") {
+    val error: AssertionError = new FailException("", Location.generate)
+  }
+}