From d6fc8207b21633436d5af1bb1bbdd23e300c2b5f 2014-11-18 18:55:12
From: Thomas Kluyver <takowl@gmail.com>
Date: 2014-11-18 18:55:12
Subject: [PATCH] %set_env should ensure environment variables are bytes on Python 2

Should fix test failures on Python 2 + Windows

---

diff --git a/IPython/core/magics/osm.py b/IPython/core/magics/osm.py
index 729fcb7..0bc533e 100644
--- a/IPython/core/magics/osm.py
+++ b/IPython/core/magics/osm.py
@@ -413,7 +413,7 @@ class OSMagics(Magics):
             err = "refusing to set env var with whitespace: '{0}'"
             err = err.format(val)
             raise UsageError(err)
-        os.environ[var] = val
+        os.environ[var] = py3compat.cast_bytes_py2(val)
         print('env: {0}={1}'.format(var,val))
 
     @line_magic