bpo-45430: Restore PEP 523 functionality.

[markshannon]

I dislike PEP 523, but we should remove it properly, not by accident 🙂

https://bugs.python.org/issue45430

[pablogsal]

LGTM

I would be good if we had a test for the basic functionality to be honest :)

[markshannon]

Adding tests might make people think we want to support it 😉

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot s390x RHEL7 LTO 3.x has failed when building commit fcb3d2f.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/all/#builders/402/builds/936) and take a look at the build logs.
4. Check if the failure is related to this commit (fcb3d2f) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/all/#builders/402/builds/936

Failed tests:

• test_pickletools
• test_pickle

Summary of the results of the build (if available):

==

Click to see traceback logs

Traceback (most recent call last):
  File "/home/dje/cpython-buildarea/3.x.edelsohn-rhel-z.lto/build/Lib/multiprocessing/resource_tracker.py", line 209, in main
    cache[rtype].remove(name)
    ^^^^^^^^^^^^^^^^^^^^^^^^^
KeyError: '/psm_a6a6bf24'


Traceback (most recent call last):
  File "/home/dje/cpython-buildarea/3.x.edelsohn-rhel-z.lto/build/Lib/multiprocessing/resource_tracker.py", line 209, in main
    cache[rtype].remove(name)
    ^^^^^^^^^^^^^^^^^^^^^^^^^
KeyError: '/psm_5dad2f24'

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot AMD64 FreeBSD Shared 3.x has failed when building commit fcb3d2f.

What do you need to do:

1. Don't panic.
2. Check the buildbot page in the devguide if you don't know what the buildbots are or how they work.
3. Go to the page of the buildbot that failed (https://buildbot.python.org/all/#builders/483/builds/945) and take a look at the build logs.
4. Check if the failure is related to this commit (fcb3d2f) or if it is a false positive.
5. If the failure is related to this commit, please, reflect that on the issue and make a new Pull Request with a fix.

You can take a look at the buildbot page here:

https://buildbot.python.org/all/#builders/483/builds/945

Failed tests:

• test_gdb
• test_concurrent_futures

Failed subtests:

• test_one_abs_arg - test.test_gdb.PyListTests
• test_bt - test.test_gdb.PyBtTests
• test_locals_after_up - test.test_gdb.PyLocalsTests
• test_idle_process_reuse_multiple - test.test_concurrent_futures.ProcessPoolForkProcessPoolExecutorTest
• test_up_then_down - test.test_gdb.StackNavigationTests
• test_print_after_up - test.test_gdb.PyPrintTests
• test_bt_full - test.test_gdb.PyBtTests
• test_basic_command - test.test_gdb.PyLocalsTests
• test_basic_command - test.test_gdb.PyListTests
• test_pyup_command - test.test_gdb.StackNavigationTests
• test_basic_command - test.test_gdb.PyPrintTests

Summary of the results of the build (if available):

== Tests result: FAILURE then FAILURE ==

407 tests OK.

10 slowest tests:

• test_multiprocessing_spawn: 9 min 2 sec
• test_unparse: 7 min 38 sec
• test_gdb: 7 min 34 sec
• test_tokenize: 6 min 38 sec
• test_concurrent_futures: 6 min 4 sec
• test_lib2to3: 4 min 47 sec
• test_multiprocessing_forkserver: 4 min 36 sec
• test_unicodedata: 3 min 26 sec
• test_capi: 3 min 20 sec
• test_peg_generator: 3 min 18 sec

1 test failed:
test_gdb

19 tests skipped:
test_dbm_gnu test_devpoll test_epoll test_idle test_ioctl
test_msilib test_readline test_spwd test_startfile test_tcl
test_tix test_tk test_ttk_guionly test_ttk_textonly test_turtle
test_winconsoleio test_winreg test_winsound test_zipfile64

2 re-run tests:
test_concurrent_futures test_gdb

Total duration: 31 min 48 sec

Click to see traceback logs

Traceback (most recent call last):
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_concurrent_futures.py", line 1038, in test_idle_process_reuse_multiple
    self.assertLessEqual(len(executor._processes), 2)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 3 not less than or equal to 2


Traceback (most recent call last):
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 1015, in test_basic_command
    self.assertMultilineMatches(bt,
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 297, in assertMultilineMatches
    self.fail(msg='%r did not match %r' % (actual, pattern))
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 'Breakpoint 1 (builtin_id) pending.\n\nBreakpoint 1, builtin_id (self=<optimized out>, v=42) at Python/bltinmodule.c:1196\n1196\t    PyObject *id = PyLong_FromVoidPtr(v);\n#4 Frame 0x800235110, for file /usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/gdb_sample.py, line 7, in bar (a=1, b=2, c=3)\n    baz(a, b, c)\nLocals for bar\na = 1\nb = 2\nc = 3\n' did not match '.*\\nargs = \\(1, 2, 3\\)\\n.*'


Traceback (most recent call last):
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 990, in test_print_after_up
    self.assertMultilineMatches(bt,
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 297, in assertMultilineMatches
    self.fail(msg='%r did not match %r' % (actual, pattern))
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: "Breakpoint 1 (builtin_id) pending.\n\nBreakpoint 1, builtin_id (self=<optimized out>, v=42) at Python/bltinmodule.c:1196\n1196\t    PyObject *id = PyLong_FromVoidPtr(v);\n#4 Frame 0x800235110, for file /usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/gdb_sample.py, line 7, in bar (a=1, b=2, c=3)\n    baz(a, b, c)\n#9 Frame 0x800235020, for file /usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/gdb_sample.py, line 12, in <module> ()\n    foo(1, 2, 3)\n'c' not found\n'b' not found\n'a' not found\n" did not match ".*\\nlocal 'c' = 3\\nlocal 'b' = 2\\nlocal 'a' = 1\\n.*"


Traceback (most recent call last):
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 793, in test_bt
    self.assertMultilineMatches(bt,
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 297, in assertMultilineMatches
    self.fail(msg='%r did not match %r' % (actual, pattern))
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 'Breakpoint 1 (builtin_id) pending.\n\nBreakpoint 1, builtin_id (self=<optimized out>, v=42) at Python/bltinmodule.c:1196\n1196\t    PyObject *id = PyLong_FromVoidPtr(v);\nTraceback (most recent call first):\n  <built-in method id of module object at remote 0x8014ac3b0>\n  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/gdb_sample.py", line 7, in bar\n    baz(a, b, c)\n  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/gdb_sample.py", line 12, in <module>\n    foo(1, 2, 3)\n' did not match '^.*\nTraceback \\(most recent call first\\):\n  <built-in method id of module object .*>\n  File ".*gdb_sample.py", line 10, in baz\n    id\\(42\\)\n  File ".*gdb_sample.py", line 7, in bar\n    baz\\(a, b, c\\)\n  File ".*gdb_sample.py", line 4, in foo\n    bar\\(a=a, b=b, c=c\\)\n  File ".*gdb_sample.py", line 12, in <module>\n    foo\\(1, 2, 3\\)\n'


Traceback (most recent call last):
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 696, in test_basic_command
    self.assertListing('   5    \n'
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 689, in assertListing
    self.assertEndsWith(actual, expected)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 291, in assertEndsWith
    self.assertTrue(actual.endswith(exp_end),
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: False is not true : 'Breakpoint 1 (builtin_id) pending.\n\nBreakpoint 1, builtin_id (self=<optimized out>, v=42) at Python/bltinmodule.c:1196\n1196\t    PyObject *id = PyLong_FromVoidPtr(v);\n   2    \n   3    def foo(a, b, c):\n   4        bar(a=a, b=b, c=c)\n   5    \n   6    def bar(a, b, c):\n  >7        baz(a, b, c)\n   8    \n   9    def baz(*args):\n  10        id(42)\n  11    \n  12    foo(1, 2, 3)\n' did not end with '   5    \n   6    def bar(a, b, c):\n   7        baz(a, b, c)\n   8    \n   9    def baz(*args):\n >10        id(42)\n  11    \n  12    foo(1, 2, 3)\n'


Traceback (most recent call last):
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 770, in test_up_then_down
    self.assertMultilineMatches(bt,
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 297, in assertMultilineMatches
    self.fail(msg='%r did not match %r' % (actual, pattern))
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 'Breakpoint 1 (builtin_id) pending.\n\nBreakpoint 1, builtin_id (self=<optimized out>, v=42) at Python/bltinmodule.c:1196\n1196\t    PyObject *id = PyLong_FromVoidPtr(v);\n#4 Frame 0x800235110, for file /usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/gdb_sample.py, line 7, in bar (a=1, b=2, c=3)\n    baz(a, b, c)\n#9 Frame 0x800235020, for file /usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/gdb_sample.py, line 12, in <module> ()\n    foo(1, 2, 3)\n#4 Frame 0x800235110, for file /usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/gdb_sample.py, line 7, in bar (a=1, b=2, c=3)\n    baz(a, b, c)\n' did not match '^.*\n#[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 10, in baz \\(args=\\(1, 2, 3\\)\\)\n    id\\(42\\)\n#[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 7, in bar \\(a=1, b=2, c=3\\)\n    baz\\(a, b, c\\)\n#[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 4, in foo \\(a=1, b=2, c=3\\)\n    bar\\(a=a, b=b, c=c\\)\n#[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 12, in <module> \\(\\)\n    foo\\(1, 2, 3\\)\n#[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 10, in baz \\(args=\\(1, 2, 3\\)\\)\n    id\\(42\\)\n#[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 7, in bar \\(a=1, b=2, c=3\\)\n    baz\\(a, b, c\\)\n$'


Traceback (most recent call last):
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 711, in test_one_abs_arg
    self.assertListing('   9    def baz(*args):\n'
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 689, in assertListing
    self.assertEndsWith(actual, expected)
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 291, in assertEndsWith
    self.assertTrue(actual.endswith(exp_end),
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: False is not true : 'Breakpoint 1 (builtin_id) pending.\n\nBreakpoint 1, builtin_id (self=<optimized out>, v=42) at Python/bltinmodule.c:1196\n1196\t    PyObject *id = PyLong_FromVoidPtr(v);\n   9    def baz(*args):\n  10        id(42)\n  11    \n  12    foo(1, 2, 3)\n' did not end with '   9    def baz(*args):\n >10        id(42)\n  11    \n  12    foo(1, 2, 3)\n'


Traceback (most recent call last):
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 813, in test_bt_full
    self.assertMultilineMatches(bt,
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 297, in assertMultilineMatches
    self.fail(msg='%r did not match %r' % (actual, pattern))
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 'Breakpoint 1 (builtin_id) pending.\n\nBreakpoint 1, builtin_id (self=<optimized out>, v=42) at Python/bltinmodule.c:1196\n1196\t    PyObject *id = PyLong_FromVoidPtr(v);\n#1 <built-in method id of module object at remote 0x8014ac3b0>\n#4 Frame 0x800235110, for file /usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/gdb_sample.py, line 7, in bar (a=1, b=2, c=3)\n    baz(a, b, c)\n#9 Frame 0x800235020, for file /usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/gdb_sample.py, line 12, in <module> ()\n    foo(1, 2, 3)\n' did not match '^.*\n#[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 7, in bar \\(a=1, b=2, c=3\\)\n    baz\\(a, b, c\\)\n#[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 4, in foo \\(a=1, b=2, c=3\\)\n    bar\\(a=a, b=b, c=c\\)\n#[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 12, in <module> \\(\\)\n    foo\\(1, 2, 3\\)\n'


Traceback (most recent call last):
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 981, in test_basic_command
    self.assertMultilineMatches(bt,
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 297, in assertMultilineMatches
    self.fail(msg='%r did not match %r' % (actual, pattern))
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: "Breakpoint 1 (builtin_id) pending.\n\nBreakpoint 1, builtin_id (self=<optimized out>, v=42) at Python/bltinmodule.c:1196\n1196\t    PyObject *id = PyLong_FromVoidPtr(v);\n#4 Frame 0x800235110, for file /usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/gdb_sample.py, line 7, in bar (a=1, b=2, c=3)\n    baz(a, b, c)\n'args' not found\n" did not match ".*\\nlocal 'args' = \\(1, 2, 3\\)\\n.*"


Traceback (most recent call last):
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 1024, in test_locals_after_up
    self.assertMultilineMatches(bt,
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 297, in assertMultilineMatches
    self.fail(msg='%r did not match %r' % (actual, pattern))
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 'Breakpoint 1 (builtin_id) pending.\n\nBreakpoint 1, builtin_id (self=<optimized out>, v=42) at Python/bltinmodule.c:1196\n1196\t    PyObject *id = PyLong_FromVoidPtr(v);\n#4 Frame 0x800235110, for file /usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/gdb_sample.py, line 7, in bar (a=1, b=2, c=3)\n    baz(a, b, c)\n#9 Frame 0x800235020, for file /usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/gdb_sample.py, line 12, in <module> ()\n    foo(1, 2, 3)\nLocals for <module>\n' did not match '^.*\nLocals for foo\na = 1\nb = 2\nc = 3\nLocals for <module>\n.*$'


Traceback (most recent call last):
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 735, in test_pyup_command
    self.assertMultilineMatches(bt,
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/test_gdb.py", line 297, in assertMultilineMatches
    self.fail(msg='%r did not match %r' % (actual, pattern))
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 'Breakpoint 1 (builtin_id) pending.\n\nBreakpoint 1, builtin_id (self=<optimized out>, v=42) at Python/bltinmodule.c:1196\n1196\t    PyObject *id = PyLong_FromVoidPtr(v);\n#4 Frame 0x800235110, for file /usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/gdb_sample.py, line 7, in bar (a=1, b=2, c=3)\n    baz(a, b, c)\n#9 Frame 0x800235020, for file /usr/home/buildbot/python/3.x.koobs-freebsd-564d/build/Lib/test/gdb_sample.py, line 12, in <module> ()\n    foo(1, 2, 3)\n' did not match '^.*\n#[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 10, in baz \\(args=\\(1, 2, 3\\)\\)\n    id\\(42\\)\n#[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 7, in bar \\(a=1, b=2, c=3\\)\n    baz\\(a, b, c\\)\n#[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 4, in foo \\(a=1, b=2, c=3\\)\n    bar\\(a=a, b=b, c=c\\)\n#[0-9]+ Frame 0x-?[0-9a-f]+, for file .*gdb_sample.py, line 12, in <module> \\(\\)\n    foo\\(1, 2, 3\\)\n$'

[vstinner]

Hi! The buildbot s390x RHEL7 LTO 3.x has failed when building commit fcb3d2f.

It seems like a legit crash on pickle tests, the 20 next builds also crashed. I created https://bugs.python.org/issue45484 to track this bug.