Document that atexit execution order is undefined (#9788)

diff --git a/Doc/library/atexit.rst b/Doc/library/atexit.rst
index eab8cd9cca34acf376c0b15a9c2f15c1ef845661..fd884d72bb1d6ad5e2b4deb7d887f1fc6dd0531c 100644 (file)
--- a/Doc/library/atexit.rst
+++ b/Doc/library/atexit.rst
@@ -12,7 +12,9 @@
 
 The :mod:`atexit` module defines a single function to register cleanup
 functions.  Functions thus registered are automatically executed upon normal
-interpreter termination.
+interpreter termination.  The order in which the functions are called is not
+defined; if you have cleanup operations that depend on each other, you should
+wrap them in a function and register that one.  This keeps :mod:`atexit` simple.
 
 .. seealso::