From e5aa71e4e1ebbbd6e43156f10bacb79a37911bc3 Mon Sep 17 00:00:00 2001
From: Ivan Kravets <me@ikravets.com>
Date: Sat, 25 Jan 2020 15:47:45 +0200
Subject: [PATCH] Fix config saving when PY2 is used

---
 platformio/project/config.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/platformio/project/config.py b/platformio/project/config.py
index ff53dd56..f277dc94 100644
--- a/platformio/project/config.py
+++ b/platformio/project/config.py
@@ -451,7 +451,7 @@ class ProjectConfig(ProjectConfigBase, ProjectConfigDirsMixin):
             del self._instances[path]
         with open(path or self.path, "w") as fp:
             fp.write(CONFIG_HEADER.strip())
-            buf = io.StringIO()
+            buf = io.BytesIO() if PY2 else io.StringIO()
             self._parser.write(buf)
             fp.write("\n\n%s\n" % buf.getvalue().strip())
         return True