fix ddc travis bot

tests/language_strong/language_strong.status

Index: tests/language_strong/language_strong.status
diff --git a/tests/language_strong/language_strong.status b/tests/language_strong/language_strong.status
index 43a0d21fb962cc5e6e4558f8e4c7df9a247eb417..c89bb5633b23e3126a7802dda54d71f2fbc66027 100644
--- a/tests/language_strong/language_strong.status
+++ b/tests/language_strong/language_strong.status
@@ -842,4 +842,11 @@ throwing_lazy_variable_test: RuntimeError # Issue 29920
 truncdiv_test: RuntimeError # Issue 29920
 type_variable_nested_test: RuntimeError # Issue 29920
 type_variable_typedef_test: RuntimeError # Issue 29920
-prefix10_negative_test: Fail # Issue 29920
+
+# This test does not generate the expected compile time error, but it also does
+# not behave correctly at runtime. We cannot record this as "Fail" without
+# confusing the DDC travis bot (as "Fail" is normally used for compile time
+# failures of _negative_tests). Remove "Skip" once we have the DDC travis bot
+# running on test.dart, OR when we fix dartanalyzer/dartdevc CommandOutput
+# classes to invert negative test status in the same way our other tools do.
+prefix10_negative_test: Skip # Issue 29920