bpo-41661: Document os.path.relpath() exception on Windows with different drives...

(cherry picked from commit 67c0b3d89c4da9750fdb43fc66d3924681b22d2e)

Co-authored-by: Zackery Spytz <zspytz@gmail.com>

diff --git a/Doc/library/os.path.rst b/Doc/library/os.path.rst
index 251df4d516eb51454fb666783903a2d781243808..d2fe4943524533623d488f85d346545a1c4c15fd 100644 (file)
--- a/Doc/library/os.path.rst
+++ b/Doc/library/os.path.rst
@@ -366,7 +366,8 @@ the :mod:`glob` module.)
    Return a relative filepath to *path* either from the current directory or
    from an optional *start* directory.  This is a path computation:  the
    filesystem is not accessed to confirm the existence or nature of *path* or
-   *start*.
+   *start*.  On Windows, :exc:`ValueError` is raised when *path* and *start*
+   are on different drives.
 
    *start* defaults to :attr:`os.curdir`.