I'm working on changes to complete the PEP 587, Python initiaization API.

New changeset 463b82a3efe8a6a9f3924a5b37482e961dffe3b8 by Victor Stinner in branch 'master':
bpo-36763: Fix Py_SetStandardStreamEncoding() (GH-13028)
https://github.com/python/cpython/commit/463b82a3efe8a6a9f3924a5b37482e961dffe3b8

New changeset 5f38b8407b071acd96da2c8cde411d0e26967735 by Victor Stinner in branch 'master':
bpo-36763: Add _PyCoreConfig_SetArgv() (GH-13030)
https://github.com/python/cpython/commit/5f38b8407b071acd96da2c8cde411d0e26967735

New changeset db7197543112954b0912e3d46e39fefcb1c3b950 by Victor Stinner in branch 'master':
bpo-36763: Rework _PyInitError API (GH-13031)
https://github.com/python/cpython/commit/db7197543112954b0912e3d46e39fefcb1c3b950

New changeset 1a9f0d8efded4bf37c864ed572beff28c43c7c77 by Victor Stinner in branch 'master':
bpo-36763: Add _PyCoreConfig_SetString() (GH-13035)
https://github.com/python/cpython/commit/1a9f0d8efded4bf37c864ed572beff28c43c7c77

New changeset cb9fbd35885a8921b9df99e801df4f82e3ba336b by Victor Stinner in branch 'master':
bpo-36763: Make _PyCoreConfig.check_hash_pycs_mode public (GH-13052)
https://github.com/python/cpython/commit/cb9fbd35885a8921b9df99e801df4f82e3ba336b

New changeset 373893ce51b0eaf0dec901e36a3e4217fbed3e32 by Victor Stinner in branch 'master':
bpo-36763: Add _PyCoreConfig._config_version (GH-13065)
https://github.com/python/cpython/commit/373893ce51b0eaf0dec901e36a3e4217fbed3e32

New changeset 70005ac0fddd8585725b92acd1bc2b8e7b81999c by Victor Stinner in branch 'master':
bpo-36763: _PyCoreConfig_SetPyArgv() preinitializes Python (GH-13037)
https://github.com/python/cpython/commit/70005ac0fddd8585725b92acd1bc2b8e7b81999c

New changeset 4631da1242fc96002a3c0462a87d087e567368aa by Victor Stinner in branch 'master':
bpo-36763: Remove _PyCoreConfig._init_main (GH-13066)
https://github.com/python/cpython/commit/4631da1242fc96002a3c0462a87d087e567368aa

I updated my PEP 587:
[Python-Dev] RFC: PEP 587 "Python Initialization Configuration": 2nd version
https://mail.python.org/pipermail/python-dev/2019-May/157290.html

New changeset 91c99873d115b9796377d5056785f2abc987520f by Victor Stinner in branch 'master':
bpo-36763: Add test for _PyCoreConfig_SetString() (GH-13275)
https://github.com/python/cpython/commit/91c99873d115b9796377d5056785f2abc987520f

New changeset 5eb8b07f87c66a9ca54fcb90737753ce76a3054d by Victor Stinner in branch 'master':
bpo-36763: InitConfigTests tests all core config (GH-13331)
https://github.com/python/cpython/commit/5eb8b07f87c66a9ca54fcb90737753ce76a3054d

New changeset dbacfc227381fbc7b3c886ea0bd7806ab3dc62c2 by Victor Stinner in branch 'master':
bpo-36763: _PyInitError always use int for exitcode (GH-13360)
https://github.com/python/cpython/commit/dbacfc227381fbc7b3c886ea0bd7806ab3dc62c2

New changeset ae239f6b0626e926613a4a1dbafa323bd41fec32 by Victor Stinner in branch 'master':
bpo-36763: Add _PyCoreConfig.parse_argv (GH-13361)
https://github.com/python/cpython/commit/ae239f6b0626e926613a4a1dbafa323bd41fec32

New changeset 9ef5dcaa0b3c7c7ba28dbb3ec0c9507d9d05e3a9 by Victor Stinner in branch 'master':
bpo-36763: Add _Py_InitializeMain() (GH-13362)
https://github.com/python/cpython/commit/9ef5dcaa0b3c7c7ba28dbb3ec0c9507d9d05e3a9

New changeset 54b43bb3bb88339b63182b3515cda3efa530ed62 by Victor Stinner in branch 'master':
bpo-36763: Add _PyCoreConfig.configure_c_stdio (GH-13363)
https://github.com/python/cpython/commit/54b43bb3bb88339b63182b3515cda3efa530ed62

New changeset 870b035bc6da96689b59dd6f79782ec6f1873617 by Victor Stinner in branch 'master':
bpo-36763: Cleanup precmdline in _PyCoreConfig_Read() (GH-13371)
https://github.com/python/cpython/commit/870b035bc6da96689b59dd6f79782ec6f1873617

New changeset fed02e15b39b6f1521ea21654be5fc0757a8720a by Victor Stinner in branch 'master':
bpo-36763: Remove _PyCoreConfig.program (GH-13373)
https://github.com/python/cpython/commit/fed02e15b39b6f1521ea21654be5fc0757a8720a

New changeset b16b4e45923f4e4dfd8e970ae4e6a934faf73b79 by Victor Stinner in branch 'master':
bpo-36763: Add PyMemAllocatorName (GH-13387)
https://github.com/python/cpython/commit/b16b4e45923f4e4dfd8e970ae4e6a934faf73b79

New changeset cab5d0741ee6adf2ae9ff5aaafe06b75b4b5bca3 by Victor Stinner in branch 'master':
bpo-36763: Add _PyCoreConfig_InitPythonConfig() (GH-13388)
https://github.com/python/cpython/commit/cab5d0741ee6adf2ae9ff5aaafe06b75b4b5bca3

New changeset 12083284c54be25abadd85781d36b63731dc1f0c by Victor Stinner in branch 'master':
bpo-36763: _Py_RunMain() doesn't call Py_Exit() anymore (GH-13390)
https://github.com/python/cpython/commit/12083284c54be25abadd85781d36b63731dc1f0c

New changeset 871ff77c1cd334a141d52b0d003c080a1928731e by Victor Stinner in branch 'master':
bpo-36763: Add _PyInitError functions (GH-13395)
https://github.com/python/cpython/commit/871ff77c1cd334a141d52b0d003c080a1928731e

New changeset b594784272d4907b1c40d3c40d17cb081aa9cf9b by Victor Stinner in branch 'master':
bpo-36763: _Py_InitializeFromArgs() argc becomes Py_ssize_t (GH-13396)
https://github.com/python/cpython/commit/b594784272d4907b1c40d3c40d17cb081aa9cf9b

New changeset bab0db6076900cd828588be8595b3cdfade7e7e9 by Victor Stinner in branch 'master':
bpo-36763: Use _PyCoreConfig_InitPythonConfig() (GH-13398)
https://github.com/python/cpython/commit/bab0db6076900cd828588be8595b3cdfade7e7e9

New changeset 410759fba80aded5247b693c60745aa16906f3bb by Victor Stinner in branch 'master':
bpo-36763: Remove _PyCoreConfig.dll_path (GH-13402)
https://github.com/python/cpython/commit/410759fba80aded5247b693c60745aa16906f3bb

New changeset 6d1c46746e17367caf8a24623cb5c9a9c4e3e036 by Victor Stinner in branch 'master':
bpo-36763: Fix Python preinitialization (GH-13432)
https://github.com/python/cpython/commit/6d1c46746e17367caf8a24623cb5c9a9c4e3e036

New changeset 425717fee1c72df464c9f85b9a8d32b9197d1035 by Victor Stinner in branch 'master':
bpo-36763: Fix encoding/locale tests in test_embed (GH-13443)
https://github.com/python/cpython/commit/425717fee1c72df464c9f85b9a8d32b9197d1035

New changeset 0f72147ce2b3d65235b41eddc6a57be40237b5c7 by Victor Stinner in branch 'master':
bpo-36763: Fix _PyRuntime.preconfig.coerce_c_locale (GH-13444)
https://github.com/python/cpython/commit/0f72147ce2b3d65235b41eddc6a57be40237b5c7

New changeset 022be02dcfdfd9011415804bb4553a33fa7ec8f3 by Victor Stinner in branch 'master':
bpo-36763: Add _PyPreConfig._config_init (GH-13481)
https://github.com/python/cpython/commit/022be02dcfdfd9011415804bb4553a33fa7ec8f3

New changeset 5edcf263581c70f6a6c2206db679e51e9418bb38 by Victor Stinner in branch 'master':
bpo-36763: Rename private Python initialization functions (GH-13511)
https://github.com/python/cpython/commit/5edcf263581c70f6a6c2206db679e51e9418bb38

New changeset 20e1e2582e5e69e43af88ff58699c8883d146acb by Victor Stinner in branch 'master':
bpo-36763: Fix _PyPreConfig_InitCompatConfig() utf8_mode (GH-13518)
https://github.com/python/cpython/commit/20e1e2582e5e69e43af88ff58699c8883d146acb

New changeset 331a6a56e9a9c72f3e4605987fabdaec72677702 by Victor Stinner in branch 'master':
bpo-36763: Implement the PEP 587 (GH-13592)
https://github.com/python/cpython/commit/331a6a56e9a9c72f3e4605987fabdaec72677702

I closed the following issues which are fixed by the implementation of the PEP 587:

* bpo-1195571
* bpo-11320
* bpo-13533
* bpo-14956
* bpo-19983
* bpo-29778
* bpo-30560
* bpo-31745
* bpo-33135
* bpo-34725
* bpo-36204

Copy of my message in bpo-19983: "This issue has been fixed by the PEP 587 in bpo-36763: when Py_Initialize() fails, it no longer calls abort() but only exit(1)."

I should maybe document this change somewhere.

In bpo-19983, I proposed a patch (init_error.patch) which changed the error message on initiallization error: "Python initialization error: %s\n" rather than "Fatal Python Error: xxx\n".

Maybe we can change that?

--

I close to leave bpo-22213 open.

bpo-32573 (missing sys.argv) is already fixed in the master branch, but I have been asked to also fix the issue in Python 3.7, so I wrote PR 13553.

TODO: I didn't implement PyWideStringList_Insert() yet.

New changeset 013a18a65167725f140c0395211050ae03501b12 by Victor Stinner in branch 'master':
bpo-36763, _testembed: enable assert() in release mode (GH-13857)
https://github.com/python/cpython/commit/013a18a65167725f140c0395211050ae03501b12

New changeset 406284173a43f5c34643133e2f132ae15a071a23 by Miss Islington (bot) in branch '3.8':
bpo-36763, _testembed: enable assert() in release mode (GH-13857)
https://github.com/python/cpython/commit/406284173a43f5c34643133e2f132ae15a071a23

Two interesting TODO.

sysmodule.c: get_xoptions()

        /* PEP432 TODO: we can reach this if xoptions is NULL in the main
        *  interpreter config. When that happens, we need to properly set
         * the `xoptions` reference in the main interpreter config as well.
         *
         * For Python 3.7, we shouldn't be able to get here due to the
         * combination of how _PyMainInterpreter_ReadConfig and _PySys_EndInit
         * work, but we expect 3.8+ to make the _PyMainInterpreter_ReadConfig
         * call optional for embedding applications, thus making this
         * reachable again.
         */

sysmodule.c: get_warnoptions()

        /* PEP432 TODO: we can reach this if warnoptions is NULL in the main
        *  interpreter config. When that happens, we need to properly set
         * the `warnoptions` reference in the main interpreter config as well.
         *
         * For Python 3.7, we shouldn't be able to get here due to the
         * combination of how _PyMainInterpreter_ReadConfig and _PySys_EndInit
         * work, but we expect 3.8+ to make the _PyMainInterpreter_ReadConfig
         * call optional for embedding applications, thus making this
         * reachable again.
         */

_PySys_ReadPreInitOptions() code should be moved somewhere closer to PyConfig_Read().

New changeset 36242fd871d0f0977e720d4fae5700774bd8c09a by Victor Stinner in branch 'master':
bpo-36763: Add PyConfig_SetWideStringList() (GH-14444)
https://github.com/python/cpython/commit/36242fd871d0f0977e720d4fae5700774bd8c09a

About the documentation: https://docs.python.org/dev/c-api/init.html doesn't link to http://docs.python.org/dev/c-api/init_config.html

The first doc should mention somewhere the new doc.

New changeset 96f581cf9d2f1d7888d2fd9bb89f19f10c0477bf by Miss Islington (bot) in branch '3.8':
bpo-36763: Add PyConfig_SetWideStringList() (GH-14444)
https://github.com/python/cpython/commit/96f581cf9d2f1d7888d2fd9bb89f19f10c0477bf

Another minor implementation issue: calling _PyCoreConfig_Read() twice calls _Py_SetArgcArgv() twice, the second call override the first _Py_SetArgcArgv() call. IMHO it should only be called once, at the first _PyCoreConfig_Read() call.

New changeset 67310023f299b5a2fad71fca449b46d280036690 by Victor Stinner in branch 'master':
bpo-36763: Use PyConfig_Clear() (GH-14445)
https://github.com/python/cpython/commit/67310023f299b5a2fad71fca449b46d280036690

New changeset 4c227e6a56a9704fe5b4e4509071796f3359f4bb by Miss Islington (bot) in branch '3.8':
bpo-36763: Use PyConfig_Clear() (GH-14445)
https://github.com/python/cpython/commit/4c227e6a56a9704fe5b4e4509071796f3359f4bb

New changeset 3842f2997fbd4dc840986aad2bb94656815e243b by Victor Stinner in branch 'master':
bpo-36763: Implement PyWideStringList_Insert() of PEP 587 (GH-15423)
https://github.com/python/cpython/commit/3842f2997fbd4dc840986aad2bb94656815e243b

New changeset a6427cb2a279c4125dc26d468bcbb3374cdc5f41 by Miss Islington (bot) in branch '3.8':
bpo-36763: Implement PyWideStringList_Insert() of PEP 587 (GH-15423)
https://github.com/python/cpython/commit/a6427cb2a279c4125dc26d468bcbb3374cdc5f41

> _PySys_ReadPreInitOptions() code should be moved somewhere closer to PyConfig_Read().

Done in PR 15431.

> The first doc should mention somewhere the new doc.

Done in PR 15433.

New changeset 1beb7c3de9c3d0e802e4267a11d937e8f024d661 by Victor Stinner in branch 'master':
bpo-36763, doc: Add links in the new C API init doc (GH-15433)
https://github.com/python/cpython/commit/1beb7c3de9c3d0e802e4267a11d937e8f024d661

New changeset 120b707a6d43452e067daa55a8fdca69f9424abc by Victor Stinner in branch 'master':
bpo-36763: PyConfig_Read() handles PySys_AddXOption() (GH-15431)
https://github.com/python/cpython/commit/120b707a6d43452e067daa55a8fdca69f9424abc

New changeset 9cbdce3917ab41856b61ac5c0f3c4ac0e203f320 by Miss Islington (bot) in branch '3.8':
bpo-36763, doc: Add links in the new C API init doc (GH-15433)
https://github.com/python/cpython/commit/9cbdce3917ab41856b61ac5c0f3c4ac0e203f320

New changeset af84a88ef8b3288da528d2f52b7d3fbafb8dc8a6 by Victor Stinner in branch '3.8':
bpo-36763: PyConfig_Read() handles PySys_AddXOption() (GH-15431) (GH-15435)
https://github.com/python/cpython/commit/af84a88ef8b3288da528d2f52b7d3fbafb8dc8a6

New changeset 9a943b4ce13fac26873b8100e89c818c5c47ac4b by Victor Stinner in branch 'master':
bpo-36763: Make Py_BytesMain() public (GH-15532)
https://github.com/python/cpython/commit/9a943b4ce13fac26873b8100e89c818c5c47ac4b

I marked the PEP 587 Status as Final. The implementation should now be complete. If there are bugs, they can be fixed in following issues :-) I close now this issue.

New changeset 1d4285a042772c7a31c4e19f8dbcbcf9b2ee3b95 by Miss Islington (bot) in branch '3.8':
bpo-36763: Make Py_BytesMain() public (GH-15532)
https://github.com/python/cpython/commit/1d4285a042772c7a31c4e19f8dbcbcf9b2ee3b95