Issue #477863: Print a warning at shutdown if gc.garbage is not empty.

2 files changed, 17 insertions, 0 deletions

diff --git a/Doc/library/gc.rst b/Doc/library/gc.rst
index a5c9e7b..29afc96 100644
--- a/Doc/library/gc.rst
+++ b/Doc/library/gc.rst
@@ -177,6 +177,15 @@ value but should not rebind it):
    If :const:`DEBUG_SAVEALL` is set, then all unreachable objects will be added to
    this list rather than freed.
 
+   .. versionchanged:: 3.2
+      If this list is non-empty at interpreter shutdown, a warning message
+      gets printed:
+
+   ::
+
+      gc: 2 uncollectable objects at shutdown:
+          Use gc.set_debug(gc.DEBUG_UNCOLLECTABLE) to list them.
+
 The following constants are provided for use with :func:`set_debug`:
 
 
@@ -197,6 +206,9 @@ The following constants are provided for use with :func:`set_debug`:
    reachable but cannot be freed by the collector).  These objects will be added to
    the ``garbage`` list.
 
+   .. versionchanged:: 3.2
+      Also print the contents of the :data:`garbage` list at interpreter
+      shutdown (rather than just its length), if it isn't empty.
 
 .. data:: DEBUG_SAVEALL
 
diff --git a/Doc/whatsnew/3.2.rst b/Doc/whatsnew/3.2.rst
index 91fd0c2..f4802a0 100644
--- a/Doc/whatsnew/3.2.rst
+++ b/Doc/whatsnew/3.2.rst
@@ -119,6 +119,11 @@ New, Improved, and Deprecated Modules
 * The :class:`ftplib.FTP` class now supports the context manager protocol
   (Contributed by Tarek Ziadé and Giampaolo Rodolà; :issue:`4972`.)
 
+* A warning message will now get printed at interpreter shutdown if
+  the :data:`gc.garbage` list isn't empty.  This is meant to make the
+  programmer aware that his code contains object finalization issues.
+  (Added by Antoine Pitrou; :issue:`477863`.)
+
 * The :func:`shutil.copytree` function has two new options:
 
   * *ignore_dangling_symlinks*: when ``symlinks=False`` (meaning that the