Index: tests/lit.cfg
===================================================================
--- tests/lit.cfg
+++ tests/lit.cfg
@@ -33,6 +33,10 @@
 except:
     build_root = ''
 config.environment['PYTHONPATH'] = '%s:%s' % (build_root, src_root)
+# LNT needs a UTF-8 locale when running in Python 3 mode. Rely on the host
+# environment to provide it rather than assume a specific UTF-8 locale is
+# present.
+config.environment['LANG'] = os.environ['LANG']
 # Don't generate .pyc files when running tests.
 config.environment['PYTHONDONTWRITEBYTECODE'] = "1"
 config.environment['SUDO_CMD'] = ""