diff --git a/scripts/build/Dyninst/testsuite.pm b/scripts/build/Dyninst/testsuite.pm
index e279eb2b..1a2faa08 100644
--- a/scripts/build/Dyninst/testsuite.pm
+++ b/scripts/build/Dyninst/testsuite.pm
@@ -189,13 +189,28 @@ sub run {
 			"LD_LIBRARY_PATH=$paths:\$LD_LIBRARY_PATH " .
 			"./runTests -64 -all -log test.log -j$args->{'ntestjobs'} $limit 1>stdout.log 2>stderr.log"
 		);
-		
+
+		## XXX do a better job here, otherwise
+		## dual watchdog messages, but at least tell the truth
 		# Being killed by the watchdog timer _should_ cause 'execute' to throw, but
 		# check it here explicitly just to be sure
-		die if _killed_by_watchdog("$base_dir/stderr.log");
+		if (_killed_by_watchdog("$base_dir/stderr.log")) {
+			$run_log->write("group test exceeded time limit, uncaught, forcing...");
+			die;
+		}
+		$run_log->write("Running in group mode succeeded, NO REPLAY NEEDED.\n");
 	} catch {
-		$run_log->write("Running in group mode failed. Running single-step mode.\n");
-		_run_single($paths, $args, $base_dir, $run_log);
+		## make sure we know it is this failure
+		if (_killed_by_watchdog("$base_dir/stderr.log")) {
+			$run_log->write("group test exceeded time limit, caught");
+		}
+		if ($args->{'replay'}) {
+			$run_log->write("Running in group mode failed. Running single-step mode.\n");
+			_run_single($paths, $args, $base_dir, $run_log);
+		}
+		else {
+			$run_log->write("Running in group mode failed, NO REPLAY.\n");
+		}
 	};
 }
 
diff --git a/scripts/build/build.pl b/scripts/build/build.pl
index 7c2d3626..83741a54 100644
--- a/scripts/build/build.pl
+++ b/scripts/build/build.pl
@@ -49,6 +49,7 @@
 	'debug-mode'			=> 0,	# undocumented debug mode
 	'limit'				=> undef,	# change group limit
 	'root'				=> undef,	# root directory name
+	'replay'			=> 1,	# replay fails in single-step
 );
 
 GetOptions(\%args,
@@ -63,6 +64,7 @@
 	'sterile!', 'hostname=s', 'debug-mode',
 	'limit=i',
 	'root=s',
+	'replay!',
 ) or pod2usage(-exitval=>2);
 
 if($args{'help'}) {
@@ -342,5 +344,6 @@ =head1 SYNOPSIS
    --hostname              Override the hostname provided by `uname`
    --limit=n               Change group test limit in testsuite.
    --root=dir              Set name/ID of root of test directory
+   --no-replay             Turn off automatic replay of failed tests.
    --help                  Print this help message
 =cut