I'm getting these validation failures today on HEAD (64 bit Linux): OVERALL SUMMARY for test run started at Mon Sep 16 16:18:39 BST 2013 3793 total tests, which gave rise to 15020 test cases, of which 11569 were skipped 28 had missing libraries 3362 expected passes 58 expected failures 0 caused framework failures 1 unexpected passes 2 unexpected failures Unexpected passes: rts linker_unload (normal) Unexpected failures: perf/compiler T5837 [stat not good enough] (normal) rts T5435_v [bad stdout] (normal) T5837 started to fail randomly after the AMP warnings patch, but the two RTS failures are new. Edward, T5435_v is something you've been working on recently - could you take a look? Here is some output that might be helpful: =====> linker_unload(normal) 2475 of 3793 [0, 0, 0] cd ./rts && $MAKE -s --no-print-directory linker_unload linker_unload.run.stdout 2>linker_unload.run.stderr *** unexpected pass for linker_unload(normal) =====> T5435_v(normal) 2479 of 3793 [0, 0, 0] cd ./rts && $MAKE -s --no-print-directory T5435_v T5435_v.run.stdout 2>T5435_v.run.stderr Actual stdout output differs from expected: --- ./rts/T5435_v.stdout 2013-09-16 15:19:05.521987217 +0100 +++ ./rts/T5435_v.run.stdout 2013-09-16 16:25:21.902356951 +0100 @@ -1,2 +1 @@ -initializer run success *** unexpected failure for T5435_v(normal) Janek