README.rst: add "export" to PYTHONPATH example

diff --git a/README.rst b/README.rst
index 92e9ab29b7357364e0fd7d255368f8adf133ef16..28ac9cddb11cdbbe3bba75df9dca24b958a1ae18 100644 (file)
--- a/README.rst
+++ b/README.rst
@@ -39,7 +39,7 @@ initialization file (``~/.bashrc`` if you use BASH). For example,
 
 .. code-block:: shell
 
-  PYTHONPATH="${PYTHONPATH}:/path/to/sage.d.git"
+  export PYTHONPATH="${PYTHONPATH}:/path/to/sage.d.git"
 
 If you would like the public bits of the library to be automatically
 imported when you start Sage, add