diff --git a/test/cctest/testcfg.py b/test/cctest/testcfg.py
index b67002f53a..69a5db2044 100644
--- a/test/cctest/testcfg.py
+++ b/test/cctest/testcfg.py
@@ -38,16 +38,20 @@ class CcTestSuite(testsuite.TestSuite):
 
   def __init__(self, name, root):
     super(CcTestSuite, self).__init__(name, root)
-    self.serdes_dir = normpath(join(root, "..", "..", "out", ".serdes"))
-    if exists(self.serdes_dir):
+    self.serdes_dir = os.path.normpath(
+        os.path.join(root, "..", "..", "out", ".serdes"))
+    if os.path.exists(self.serdes_dir):
       shutil.rmtree(self.serdes_dir, True)
     os.makedirs(self.serdes_dir)
 
   def ListTests(self, context):
-    shell = join(context.shell_dir, self.shell())
     if utils.IsWindows():
       shell += '.exe'
-    output = commands.Execute([shell, '--list'])
+    shell = os.path.abspath(os.path.join(context.shell_dir, self.shell()))
+    output = commands.Execute([context.command_prefix,
+                               shell,
+                               '--list',
+                               context.extra_flags])
     if output.exit_code != 0:
       print output.stdout
       print output.stderr
@@ -66,7 +70,7 @@ class CcTestSuite(testsuite.TestSuite):
 
   def GetFlagsForTestCase(self, testcase, context):
     testname = testcase.path.split(os.path.sep)[-1]
-    serialization_file = join(self.serdes_dir, "serdes_" + testname)
+    serialization_file = os.path.join(self.serdes_dir, "serdes_" + testname)
     serialization_file += ''.join(testcase.flags).replace('-', '_')
     return (testcase.flags + [testcase.path] + context.mode_flags +
             ["--testing_serialization_file=" + serialization_file])
diff --git a/tools/run-tests.py b/tools/run-tests.py
index 5d90d1947e..a49f6560a6 100755
--- a/tools/run-tests.py
+++ b/tools/run-tests.py
@@ -60,6 +60,13 @@ MODE_FLAGS = {
                  "--enable-slow-asserts", "--debug-code", "--verify-heap"],
     "release" : ["--nobreak-on-abort", "--nodead-code-elimination"]}
 
+SUPPORTED_ARCHS = ["android_arm",
+                   "android_ia32",
+                   "arm",
+                   "ia32",
+                   "mipsel",
+                   "x64"]
+
 
 def BuildOptions():
   result = optparse.OptionParser()
@@ -150,7 +157,7 @@ def ProcessOptions(options):
     options.arch = ARCH_GUESS
   options.arch = options.arch.split(",")
   for arch in options.arch:
-    if not arch in ['ia32', 'x64', 'arm', 'mipsel']:
+    if not arch in SUPPORTED_ARCHS:
       print "Unknown architecture %s" % arch
       return False
 
diff --git a/tools/testrunner/local/commands.py b/tools/testrunner/local/commands.py
index 716d7ba8fb..01f170dc87 100644
--- a/tools/testrunner/local/commands.py
+++ b/tools/testrunner/local/commands.py
@@ -131,6 +131,7 @@ def CheckedUnlink(name):
 
 
 def Execute(args, verbose=False, timeout=None):
+  args = [ c for c in args if c != "" ]
   (fd_out, outname) = tempfile.mkstemp()
   (fd_err, errname) = tempfile.mkstemp()
   try:
diff --git a/tools/testrunner/local/execution.py b/tools/testrunner/local/execution.py
index 0adf9c9071..6004367913 100644
--- a/tools/testrunner/local/execution.py
+++ b/tools/testrunner/local/execution.py
@@ -168,11 +168,10 @@ class Runner(object):
     if utils.IsWindows():
       shell += ".exe"
     cmd = ([self.context.command_prefix] +
-           [os.path.join(self.context.shell_dir, shell)] +
+           [os.path.abspath(os.path.join(self.context.shell_dir, shell))] +
            d8testflag +
            test.suite.GetFlagsForTestCase(test, self.context) +
            [self.context.extra_flags])
-    cmd = [ c for c in cmd if c != "" ]
     return cmd