bpo-26468: Doc: improve the documentation of shutil.copy2 when it can fail. (GH-13765)

diff --git a/Doc/library/shutil.rst b/Doc/library/shutil.rst
index 88c5f62dd4c99fdb011cd40c08d991713d50ebab..174b7e875a38a484ccffe1827d7392622dd92052 100644 (file)
--- a/Doc/library/shutil.rst
+++ b/Doc/library/shutil.rst
@@ -187,7 +187,8 @@ Directory and files operations
    However, this functionality is not available on all platforms.
    On platforms where some or all of this functionality is
    unavailable, :func:`copy2` will preserve all the metadata
-   it can; :func:`copy2` never returns failure.
+   it can; :func:`copy2` never raises an exception because it
+   cannot preserve file metadata.
 
    :func:`copy2` uses :func:`copystat` to copy the file metadata.
    Please see :func:`copystat` for more information