print invalid child messages

cleantest.icl

@@ -24,7 +24,7 @@ import System.Options
 import System.Process
 import Testing.Options
 import Testing.TestEvents
-from Text import <+, class Text(join,replaceSubString,split,trim), instance Text String
+from Text import <+, class Text(join,replaceSubString,split,trim,concat), instance Text String
 import Text.GenJSON
 import Text.GenParse
 import Text.GenPrint
@@ -320,7 +320,10 @@ where
 			# io = emit (EndEvent
 				{ name    = r.TestRun.name
 				, event   = event
-				, message = "Failed to read child messages"
+				, message = concat
+					[ "Failed to read child messages:"
+					: flatten [["\n    ", outp] \\ outp <- output.lines & Nothing <- results]
+					]
 				}) io
 			= return event r io w
 		# ee = mergeResults $ map fromJust results