Python を 3.14 から 3.15 に上げると動かなくなること

$ cat read.py
with open("scores.csv") as f:
    print(f.read().splitlines())

$ env LANG=ja_JP.SJIS python3.14 read.py
['名前,点数', '佐藤,80']
$ echo $?
0

$ env LANG=ja_JP.SJIS python3.14 -X warn_default_encoding read.py
/app/read.py:1: EncodingWarning: 'encoding' argument not specified
  with open("scores.csv") as f:
['名前,点数', '佐藤,80']

$ env LANG=ja_JP.SJIS python3.15 read.py
Traceback (most recent call last):
  File "/app/read.py", line 2, in <module>
    print(f.read().splitlines())
          ~~~~~~^^
  File "<frozen codecs>", line 325, in decode
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x96 in position 0: invalid start byte
$ echo $?
1

$ env LANG=ja_JP.SJIS python3.15 -X utf8=0 read.py
['名前,点数', '佐藤,80']
$ echo $?
0

$ cat read.py
with open("scores.csv", encoding="cp932") as f:
    print(f.read().splitlines())

$ env LANG=ja_JP.SJIS python3.15 read.py
['名前,点数', '佐藤,80']
$ echo $?
0

$ cat bday.py
from datetime import datetime
 
print(datetime.strptime("10-31", "%m-%d"))

$ python3.14 bday.py
/app/bday.py:3: DeprecationWarning: Parsing dates involving a day of month without a year specified is ambiguous
and fails to parse leap day. The default behavior will change in Python 3.15
to either always raise an exception or to use a different default year (TBD).
To avoid trouble, add a specific year to the input & format.
See https://github.com/python/cpython/issues/70647.
  print(datetime.strptime("10-31", "%m-%d"))
1900-10-31 00:00:00
$ echo $?
0

$ python3.15 bday.py
Traceback (most recent call last):
  File "/app/bday.py", line 3, in <module>
    print(datetime.strptime("10-31", "%m-%d"))
          ~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.15/_strptime.py", line 844, in _strptime_datetime_datetime
    tt, fraction, gmtoff_fraction = _strptime(data_string, format)
                                    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.15/_strptime.py", line 559, in _strptime
    format_regex = _TimeRE_cache.compile(format)
  File "/usr/local/lib/python3.15/_strptime.py", line 504, in compile
    return re_compile(self.pattern(format), IGNORECASE)
                      ~~~~~~~~~~~~^^^^^^^^
  File "/usr/local/lib/python3.15/_strptime.py", line 485, in pattern
    raise ValueError(
    ...<4 lines>...
        "See https://github.com/python/cpython/issues/70647.")
ValueError: Day of month directive '%d' may not be used without a year directive. Parsing dates involving a day of month without a year is ambiguous and fails to parse leap day. Add a year to the input and format. See https://github.com/python/cpython/issues/70647.
$ echo $?
1

$ cat bday.py
from datetime import datetime
 
d = datetime.strptime("2026-10-31", "%Y-%m-%d")
print(d.month, d.day)

$ python3.15 bday.py
10 31
$ echo $?
0

$ python3.14 -c 'import sre_yield; print(list(sre_yield.AllStrings("[ab]c")))'
['ac', 'bc']
$ echo $?
0

$ python3.15 -c 'import sre_yield; print(list(sre_yield.AllStrings("[ab]c")))'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
    import sre_yield; print(list(sre_yield.AllStrings("[ab]c")))
    ^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.15/site-packages/sre_yield/__init__.py", line 33, in <module>
    import sre_constants
ModuleNotFoundError: No module named 'sre_constants'
$ echo $?
1

$ python3.15 -c 'import exrex; print(list(exrex.generate("[ab]c")))'
['ac', 'bc']
$ echo $?
0

$ cat point.py
from typing import NamedTuple
 
Point = NamedTuple("Point", x=int, y=int)
print(Point(1, 2))

$ python3.14 point.py
/app/point.py:3: DeprecationWarning: Creating NamedTuple classes using keyword arguments is deprecated and will be disallowed in Python 3.15. Use the class-based or functional syntax instead.
  Point = NamedTuple("Point", x=int, y=int)
Point(x=1, y=2)
$ echo $?
0

$ python3.15 point.py
Traceback (most recent call last):
  File "/app/point.py", line 3, in <module>
    Point = NamedTuple("Point", x=int, y=int)
TypeError: NamedTuple() got an unexpected keyword argument 'x'
$ echo $?
1

$ cat point.py
from typing import NamedTuple
 
Point = NamedTuple("Point", [("x", int), ("y", int)])
print(Point(1, 2))

$ python3.15 point.py
Point(x=1, y=2)
$ echo $?
0

$ cat empty.py
from typing import TypedDict
 
Options = TypedDict("Options")
print(Options())

$ python3.14 empty.py
/app/empty.py:3: DeprecationWarning: Failing to pass a value for the 'fields' parameter is deprecated and will be disallowed in Python 3.15. To create a TypedDict class with 0 fields using the functional syntax, pass an empty dictionary, e.g. `Options = TypedDict('Options', {})`.
  Options = TypedDict("Options")
{}
$ echo $?
0

$ python3.15 empty.py
Traceback (most recent call last):
  File "/app/empty.py", line 3, in <module>
    Options = TypedDict("Options")
TypeError: TypedDict() missing 1 required positional argument: 'fields'
$ echo $?
1

$ cat empty.py
from typing import TypedDict
 
Options = TypedDict("Options", {})
print(Options())

$ python3.15 empty.py
{}
$ echo $?
0