Make it easier to run and test Python on systems with restrict crypto policies:

* add requires_hashdigest to test.support to check if a hash digest algorithm is available and working
* avoid MD5 in test_hmac
* replace MD5 with SHA256 in test_tarfile
* mark network tests that require MD5 for MD5-based digest auth or CRAM-MD5


https://bugs.python.org/issue38270

* subprocess.Popen now longer uses posix_spawn() if uid, gid or gids are set.
* test_subprocess: add "nobody" and "nfsnobody" group names for test_group().
* test_subprocess: test_user() and test_group() are now also tested with close_fds=False.

Add option -a to Tools/Scripts/pathfix.py script: add flags.

bpo-38140: Document offsets in PyMemberDef
Co-Authored-By: Ammar Askar <ammar_askar@hotmail.com>

Add docs about return and raise exception on asyncio.run





https://bugs.python.org/issue38260



Automerge-Triggered-By: @asvetlov

* search_for_prefix() directly calls reduce() if found is greater
  than 0.
* Add calculate_pybuilddir() subfunction.
* search_for_prefix(): add path string buffer for readability.
* Fix some error handling code paths: release resources on error.
* calculate_read_pyenv(): rename tmpbuffer to filename.
* test.pythoninfo now also logs windows.dll_path

Add test_init_pybuilddir() and test_init_pyvenv_cfg() to test_embed
to test pyvenv.cfg and pybuilddir.txt configuration files.

Fix sysconfig._generate_posix_vars(): pybuilddir.txt uses UTF-8
encoding, not ASCII.

Fixes an issue caught after merge of PR 16005.

Tightened test assertions to check the entire assertion message.

The fix in PR 13261 handled the underlying issue about the spec for specific methods not being applied correctly, but it didn't fix the issue that was causing the misleading error message.

The code currently grabs a list of responses from _call_matcher (which may include exceptions). But it doesn't reach inside the list when checking if the result is an exception. This results in a misleading error message when one of the provided calls does not match the spec.


https://bugs.python.org/issue36871



Automerge-Triggered-By: @gpshead

Py_SetPath() now sets sys.executable to the program full path
(Py_GetProgramFullPath()), rather than to the program name
(Py_GetProgramName()).

Fix also memory leaks in pathconfig_set_from_config().

Multiprocessing test test_mymanager() now also expects -SIGTERM, not
only exitcode 0.

bpo-30356: BaseManager._finalize_manager() sends SIGTERM to the
manager process if it takes longer than 1 second to stop, which
happens on slow buildbots.

Multiprocessing tests: increase test_queue_feeder_donot_stop_onexc()
timeout from 1 to 60 seconds.

This fixes the exception '`ValueError: invalid literal for int() with base 10`
if `str(gdbval)` returns a hexadecimal value (e.g. '0xa0'). This is the case if
the output-radix is set to 16 in gdb. See
https://sourceware.org/gdb/onlinedocs/gdb/Numbers.html for more information.

Refactor path configuration code:

* read_pth_file() now returns PyStatus to report errors, rather than
  calling Py_FatalError().
* Move argv0_path and zip_path buffers out of PyCalculatePath
  structures.
* On Windows, _PyPathConfig.home is now preferred over PyConfig.home.

* _PyConfig_InitPathConfig() now starts by copying the global path
  configuration, and then override values set in PyConfig.
* _PyPathConfig_Calculate() implementations no longer override
  _PyPathConfig fields which are already computed. For example,
  if _PyPathConfig.prefix is not NULL, leave it unchanged.
* If Py_SetPath() has been called, _PyConfig_InitPathConfig() doesn't
  call _PyPathConfig_Calculate() anymore.
* _PyPathConfig_Calculate() no longer uses PyConfig,
  except to initialize PyCalculatePath structure.
* pathconfig_calculate(): remove useless temporary
  "_PyPathConfig new_config" variable.
* calculate_module_search_path(): remove hack to workaround memory
  allocation failure, call Py_FatalError() instead.
* Fix get_program_full_path(): handle memory allocation failure.

Add missing "return;" (to not dereference NULL pointer).

Python now dumps path configuration if it fails to import the Python
codecs of the filesystem and stdio encodings.

Edit: `math.pow` changes removed on Mark's request.


https://bugs.python.org/issue38237



Automerge-Triggered-By: @rhettinger

* If Py_SetPath() has been called, _PyConfig_InitPathConfig() now
  uses its value.
* Py_Initialize() now longer copies path configuration from PyConfig
  to the global path configuration (_Py_path_config).

Based on a comment from @asvetlov https://github.com/python/cpython/pull/15735#discussion_r323619076, this removes the provisional note for ``asyncio.run()`` in the documentation.

Automerge-Triggered-By: @1st1

The DLL path is not computed from any user configuration and cannot
be configured by PyConfig. Instead, add a new _Py_dll_path global variable.

Remove _PyConfig_SetPathConfig(): replaced with _PyPathConfig_Init().

Py_Initialize() now longer sets the "global path configuration",
but only initialize _Py_dll_path.

ProactorDatagramTransportTests tests are too close to the
implementation.

It did not list the argument added in d4cc7bf9.


https://bugs.python.org/issue6559



Automerge-Triggered-By: @gpshead