--- a/tests/run-tests.py	Thu Mar 11 15:32:24 2010 +0100
+++ b/tests/run-tests.py	Mon Mar 22 01:36:12 2010 -0400
@@ -842,6 +842,7 @@
     os.environ["EMAIL"] = "Foo Bar <foo.bar@example.com>"
     os.environ['CDPATH'] = ''
     os.environ['COLUMNS'] = '80'
+    os.environ['GREP_OPTIONS'] = ''
     os.environ['http_proxy'] = ''
 
     global TESTDIR, HGTMP, INST, BINDIR, PYTHONDIR, COVERAGE_FILE