Skip the test failing randomly because of known race condition.

Skip the test to fix macOS buildbots until a decision is made on the
proper fix for the race condition.

(cherry picked from commit 550ee05)

…les (GH-4977) (#4979)

This is more complicated than it should be because we need to preserve the
useful mtime-based regeneration feature that lib2to3.pgen2.driver.load_grammar
has. We only look for the pickled grammar file with pkgutil.get_data and only if
the source file does not exist.
(cherry picked from commit 8a58771)

(cherry picked from commit d11e8e0)

)

(cherry picked from commit 4f146f9)

* Fix typos
* Change warning text
* Add test
(cherry picked from commit a8f4e15)

In pydoc.py, the reference to Python' documentation was in http.
The link has been updated to use https.
(cherry picked from commit e5681b9)

(cherry picked from commit e325608)

(cherry picked from commit 6c6d3a4)

Move other test to more proper place.
(cherry picked from commit e8ed965)

…5081)

Updates documentation for generator expressions in classes tutorial: Clarify usage of ambiguous term "brackets" by replacing with "square brackets". Updated subsequent lines to respect line breaks. (GH-5079)
(cherry picked from commit f190eb5)

The comment was added in 3abca12.
In d78448e, it was changed to
use PyArg_ParseTuple instead.

(cherry picked from commit 78e24d4)

(cherry picked from commit 65f2a6d)

It's more trouble than it's worth, since AppVeyor only checks the HEAD commit of a PR rather than the full diff against the base branch to decide which files changed.
(cherry picked from commit 7f7de37)

…rnal link (GH-5157) (GH-5160)

In lexical analysis reference documentation, the internal link to
the string literal concatenation section was written as`.. _string-catenation:`.
Changed that to `.. _string-concatenation:`.
(cherry picked from commit 3764bb0)

(cherry picked from commit ae12f5d)

glibc has removed Sun RPC. Use replacement libtirpc headers and library in
nis module

Signed-off-by: Christian Heimes <christian@python.org>
(cherry picked from commit f3031b8)

The code example that demonstrate how to use enum.Flag was missing
the import of enum.auto.
(cherry picked from commit 0f31c74)

`os.path.is*()` can return False if the file can't be accessed.
The behaviour is documented in details in `os.path.exists()`.
Link to `os.path.exists()` from `os.path.is*()`.
(cherry picked from commit b3dd18d)

Clarify that on Windows, path must be a directory.
On Unix, path can be a file or a directory.
(cherry picked from commit ee3b835)