Add some warnings about AcceptEnv to env var setting bits.

Re #398

1 files changed, 10 insertions, 0 deletions

diff --git a/paramiko/channel.py b/paramiko/channel.py
index 7689b266..3b6a59df 100644
--- a/paramiko/channel.py
+++ b/paramiko/channel.py
@@ -292,6 +292,10 @@ class Channel (ClosingContextManager):
             This operation is additive - i.e. the current environment is not
             reset before the given environment variables are set.
 
+        .. warning::
+            Servers may silently reject some environment variables; see the
+            warning in `set_environment_variable` for details.
+
         :param dict environment:
             a dictionary containing the name and respective values to set
         :raises SSHException:
@@ -310,6 +314,12 @@ class Channel (ClosingContextManager):
         """
         Set the value of an environment variable.
 
+        .. warning::
+            The server may reject this request depending on its ``AcceptEnv``
+            setting; such rejections will fail silently (which is common client
+            practice for this particular request type). Make sure you
+            understand your server's configuration before using!
+
         :param str name: name of the environment variable
         :param str value: value of the environment variable