Index: lld/trunk/test/lit.cfg.py
===================================================================
--- lld/trunk/test/lit.cfg.py
+++ lld/trunk/test/lit.cfg.py
@@ -94,7 +94,10 @@
 tar_executable = lit.util.which('tar', config.environment['PATH'])
 if tar_executable:
     tar_version = subprocess.Popen(
-        [tar_executable, '--version'], stdout=subprocess.PIPE, env={'LANG': 'C'})
-    if 'GNU tar' in tar_version.stdout.read().decode():
+        [tar_executable, '--version'],
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+        env={'LANG': 'C'})
+    sout, _ = tar_version.communicate()
+    if 'GNU tar' in sout.decode():
         config.available_features.add('gnutar')
-    tar_version.wait()