gh-140482: Avoid changing terminal settings in test_pty

[colesbury]

The previous test_spawn_doesnt_hang test had a few problems:

• It would cause ENV CHANGED failures if other tests were running concurrently due to stty changes
• Typing while the test was running could cause it to fail

• Issue: Test suite sometimes leaves terminal in -echo #140482

[bedevere-bot]

🤖 New build scheduled with the buildbot fleet by @colesbury for commit d89f1b7 🤖

Results will be shown at:

https://buildbot.python.org/all/#/grid?branch=refs%2Fpull%2F142202%2Fmerge

If you want to schedule another build, you need to add the 🔨 test-with-buildbots label again.

[warsaw]

I ran this branch many times with both make test and make quicktest on macOS 26.1 and could never trigger the env changed warnings. The changes here seem correct, so I'll approve it, although I notice that CI is failing.

[colesbury]

although I notice that CI is failing

The Android (x86_64) failures is unrelated and failing on other PRs

[miss-islington-app]

Thanks @colesbury for the PR 🌮🎉.. I'm working now to backport this PR to: 3.13.
🐍🍒⛏🤖

[miss-islington-app]

Thanks @colesbury for the PR 🌮🎉.. I'm working now to backport this PR to: 3.14.
🐍🍒⛏🤖

[bedevere-app]

GH-142238 is a backport of this pull request to the 3.13 branch.

[bedevere-app]

GH-142239 is a backport of this pull request to the 3.14 branch.

[bedevere-bot]

⚠️⚠️⚠️ Buildbot failure ⚠️⚠️⚠️

Hi! The buildbot AMD64 Debian root 3.x (tier-1) has failed when building commit c0c6514.

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/#/builders/345/builds/12810) and take a look at the build logs.
4. Check if the failure is related to this commit (c0c6514) 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/#/builders/345/builds/12810

Failed tests:

• test_http_cookies
• test_ctypes
• test_tokenize
• test_tools
• test_pickle

Failed subtests:

• test_framing_many_objects - test.test_pickle.CPicklerTests.test_framing_many_objects
• test_random_files - test.test_tokenize.TestRoundtrip.test_random_files
• test_unquote_large - test.test_http_cookies.CookieTests.test_unquote_large
• test_freeze_simple_script - test.test_tools.test_freeze.TestFreeze.test_freeze_simple_script

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

==

Click to see traceback logs

Traceback (most recent call last): File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/test/test_tokenize.py", line 2190, in test_random_filesself.check_roundtrip(f) ~~~~~~~~~~~~~~~~~~~~^^^ File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/test/test_tokenize.py", line 2027, in check_roundtrip tokens2_from5 = [tok[:2] for tok in tokenize.tokenize(readline5)] ~~~~~~~~~~~~~~~~~^^^^^^^^^^^ File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/tokenize.py", line 498, in tokenizeyield from _generate_tokens_from_c_tokenizer(rl_gen.__next__, encoding, extra_tokens=True) File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/tokenize.py", line 589, in _generate_tokens_from_c_tokenizeryield TokenInfo._make(info) ~~~~~~~~~~~~~~~^^^^^^ File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/collections/__init__.py", line 456, in _makeif _len(result) != num_fields: ~~~~^^^^^^^^TypeError: object of type 'type' has no len() Traceback (most recent call last): File "/root/buildarea/3.x.angelico-debian-amd64/build/Tools/freeze/freeze.py", line 494, in <module> main() ~~~~^^ File "/root/buildarea/3.x.angelico-debian-amd64/build/Tools/freeze/freeze.py", line 392, in main files = makefreeze.makefreeze(base, dict, debug, custom_entry_point, fail_import) File "/root/buildarea/3.x.angelico-debian-amd64/build/Tools/freeze/makefreeze.py", line 52, in makefreeze writecode(outfp, mangled, str) ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^ File "/root/buildarea/3.x.angelico-debian-amd64/build/Tools/freeze/makefreeze.py", line 83, in writecodeprint('%d,'% c, file=fp, end='') ~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^AttributeError: 'int' object has no attribute 'write' Traceback (most recent call last): File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/test/test_tools/test_freeze.py", line 35, in test_freeze_simple_script executable = helper.freeze(python, scriptfile, outdir) File "/root/buildarea/3.x.angelico-debian-amd64/build/Tools/freeze/test/freeze.py", line 169, in freeze _run_quiet([python, '-E', FREEZE, '-o', outdir, scriptfile], cwd=outdir) ~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/root/buildarea/3.x.angelico-debian-amd64/build/Tools/freeze/test/freeze.py", line 35, in _run_quietreturn subprocess.run( ~~~~~~~~~~~~~~^ cmd, ^^^^...<3 lines>... check=True, ^^^^^^^^^^^ ) ^ File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/subprocess.py", line 576, in runraise CalledProcessError(retcode, process.args, output=stdout, stderr=stderr) subprocess.CalledProcessError: Command '['/tmp/test_python_ptogmdlk/tmpyts3ic1l/python-installation/bin/python3', '-E', '/root/buildarea/3.x.angelico-debian-amd64/build/Tools/freeze/freeze.py', '-o', '/tmp/test_python_ptogmdlk/tmpyts3ic1l', '/tmp/test_python_ptogmdlk/tmpyts3ic1l/app.py']' returned non-zero exit status 1. Traceback (most recent call last): File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/test/test_tokenize.py", line 2190, in test_random_filesself.check_roundtrip(f) ~~~~~~~~~~~~~~~~~~~~^^^ File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/test/test_tokenize.py", line 2034, in check_roundtrip untokenized_code = tokenize.untokenize(tokenize.tokenize(readline)) File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/tokenize.py", line 341, in untokenize out = ut.untokenize(iterable) File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/tokenize.py", line 262, in untokenizeself.add_whitespace(start) ~~~~~~~~~~~~~~~~~~~^^^^^^^ File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/tokenize.py", line 180, in add_whitespaceself.add_backslash_continuation(start) ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^TypeError: 'Untokenizer' object is not callable Traceback (most recent call last): File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/test/pickletester.py", line 3633, in test_framing_many_objectsself.check_frame_opcodes(pickled) ~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^ File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/test/pickletester.py", line 3582, in check_frame_opcodesfor op, arg, pos in pickletools.genops(pickled): ~~~~~~~~~~~~~~~~~~^^^^^^^^^ File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/pickletools.py", line 2285, in _genopsraiseValueError("at position %s, opcode %r unknown"% ( "<unknown>"if pos isNoneelse pos, code)) ValueError: at position 188258, opcode b'M' unknown Traceback (most recent call last): File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/test/test_http_cookies.py", line 162, in test_unquote_large C.load(data) ~~~~~~^^^^^^ File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/http/cookies.py", line 518, in loadself.__parse_string(rawdata) ~~~~~~~~~~~~~~~~~~~^^^^^^^^^ File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/http/cookies.py", line 567, in __parse_string parsed_items.append((TYPE_KEYVALUE, key, self.value_decode(value))) ~~~~~~~~~~~~~~~~~^^^^^^^ File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/http/cookies.py", line 594, in value_decodereturn _unquote(val), val ~~~~~~~~^^^^^ File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/http/cookies.py", line 213, in _unquotereturn _unquote_sub(_unquote_replace, str) File "/root/buildarea/3.x.angelico-debian-amd64/build/Lib/http/cookies.py", line 190, in _unquote_replaceif m[1]: ~^^^TypeError: unsupported operand type(s) for +: 're.Match' and 'int'