posix.link, termios.error, warn() error, closefd=False for std in/out by youknowone · Pull Request #6942 · RustPython/RustPython

youknowone · 2026-02-01T17:01:27Z

Summary by CodeRabbit

New Features
- Added follow_symlinks parameter control to the link function for enhanced symlink handling.
Bug Fixes
- Improved error propagation in warnings functionality—errors are now properly reported instead of silently ignored.
Chores
- Refined internal error handling and resource management for improved stability.

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- Use linkat() with AT_SYMLINK_FOLLOW on Unix - Raise NotImplementedError on non-Unix when follow_symlinks=False - Register link in supports_follow_symlinks

- Replace manual exception creation with new_os_subtype_error in termios - Remove redundant .to_owned() calls in os.link() error messages

- Prevent closing underlying fd when stdio wrappers are dropped - Remove expectedFailure from test_fdopen in test_os.py

coderabbitai · 2026-02-01T17:01:36Z

📝 Walkthrough

Walkthrough

This PR updates error handling and OS-specific function behavior across multiple stdlib modules. Changes include refactoring termios error construction to use a structured pattern, adding follow_symlinks parameter support to os.link with platform-specific implementations, propagating warning errors instead of silencing them, and adjusting file descriptor closure behavior for standard IO streams.

Changes

Cohort / File(s)	Summary
Error Construction Refactor `crates/stdlib/src/termios.rs`	Replaces generic exception creation with structured os_subtype_error pattern, updating parameter arrangement to supply OS-specific errno separately from error message.
OS Link Enhancement `crates/vm/src/stdlib/os.rs`	Adds follow_symlinks parameter to link function; implements platform-specific behavior using libc::linkat on Unix with flag control, and conditional NotImplementedError on non-Unix platforms when follow_symlinks is false. Updates support metadata to advertise conditional availability.
Error Propagation `crates/vm/src/stdlib/warnings.rs`	Changes warning error handling from ignored (let _ =) to propagated (?), allowing failures to contribute to PyResult flow.
File Descriptor Management `crates/vm/src/vm/mod.rs`	Adds closefd: false to OpenArgs for standard IO wrappers to prevent closing underlying file descriptors on drop.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~22 minutes

Possibly related PRs

Integrate OSError creations into OSErrorBuilder #6443: Centralizes OSError/OSErrorBuilder exception construction that the termios refactor aligns with.
new_last_{os,errno}_error #6381: Refactors errno/os error helpers (new_last_errno_error) that relate to the termios error handling pattern changes.

Poem

🐰 Errors now flow where once they were hushed,
Symlinks dance conditional, platform-blessed,
File descriptors cling to life as they should,
A refactored warren of errno so good! ✨

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 42.86% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title directly lists all four main changes made in the PR: posix.link enhancement, termios.error refactoring, warn() error propagation, and closefd=False for standard I/O.

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github-actions · 2026-02-01T17:01:57Z

📦 Library Dependencies

The following Lib/ modules were modified. Here are their dependencies:

[ ] lib: cpython/Lib/os.py
[ ] test: cpython/Lib/test/test_os.py (TODO: 16)
[ ] test: cpython/Lib/test/test_popen.py

dependencies:

os (native: os.path, sys)
- _collections_abc, abc, stat

dependent tests: (158 tests)

os: test___all__ test__osx_support test_argparse test_ast test_asyncio test_atexit test_base64 test_baseexception test_bdb test_bool test_builtin test_bytes test_bz2 test_c_locale_coercion test_calendar test_cmd_line test_cmd_line_script test_codecs test_compile test_compileall test_concurrent_futures test_configparser test_contextlib test_ctypes test_dbm test_dbm_dumb test_dbm_sqlite3 test_decimal test_devpoll test_doctest test_dtrace test_eintr test_email test_ensurepip test_enum test_epoll test_exception_hierarchy test_exceptions test_faulthandler test_fcntl test_file test_file_eintr test_filecmp test_fileinput test_fileio test_float test_fnmatch test_fork1 test_fractions test_fstring test_ftplib test_future_stmt test_genericalias test_genericpath test_getpass test_gettext test_glob test_graphlib test_gzip test_hash test_hashlib test_http_cookiejar test_httplib test_httpservers test_importlib test_inspect test_io test_ioctl test_json test_kqueue test_largefile test_linecache test_locale test_logging test_lzma test_mailbox test_marshal test_math test_mimetypes test_mmap test_msvcrt test_multiprocessing_fork test_multiprocessing_forkserver test_multiprocessing_main_handling test_multiprocessing_spawn test_ntpath test_openpty test_optparse test_os test_pathlib test_pkg test_pkgutil test_platform test_plistlib test_poll test_popen test_posix test_posixpath test_pty test_py_compile test_pyexpat test_random test_regrtest test_repl test_reprlib test_robotparser test_runpy test_script_helper test_selectors test_shelve test_shutil test_signal test_site test_smtpnet test_socket test_socketserver test_sqlite3 test_ssl test_stat test_string_literals test_structseq test_subprocess test_support test_sys test_sysconfig test_tabnanny test_tarfile test_tempfile test_termios test_thread test_threading test_tokenize test_tools test_trace test_tty test_typing test_unicode_file test_unicode_file_functions test_unittest test_univnewlines test_urllib test_urllib2 test_urllib2_localnet test_urllib2net test_urllibnet test_uuid test_venv test_wait3 test_wait4 test_webbrowser test_winapi test_winreg test_wsgiref test_xml_etree test_zipfile test_zipimport test_zoneinfo test_zstd

Legend:

[+] path exists in CPython
[x] up-to-date, [ ] outdated

youknowone added 4 commits February 2, 2026 01:53

Add follow_symlinks support to os.link()

24b6f48

- Use linkat() with AT_SYMLINK_FOLLOW on Unix - Raise NotImplementedError on non-Unix when follow_symlinks=False - Register link in supports_follow_symlinks

Use new_os_subtype_error for termios error construction

188d438

- Replace manual exception creation with new_os_subtype_error in termios - Remove redundant .to_owned() calls in os.link() error messages

Propagate errors from warnings.warn() calls

fce2d78

Set closefd=false for stdio file objects in VM init

1132f66

- Prevent closing underlying fd when stdio wrappers are dropped - Remove expectedFailure from test_fdopen in test_os.py

youknowone marked this pull request as ready for review February 1, 2026 17:01

youknowone marked this pull request as draft February 1, 2026 17:01

youknowone marked this pull request as ready for review February 1, 2026 23:05

youknowone merged commit ab6114d into RustPython:main Feb 1, 2026
14 checks passed

youknowone deleted the os-fix branch February 1, 2026 23:11

coderabbitai bot mentioned this pull request Feb 3, 2026

Update os from v3.14.2 and fix nt,posix,_os #6958

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posix.link, termios.error, warn() error, closefd=False for std in/out#6942

posix.link, termios.error, warn() error, closefd=False for std in/out#6942
youknowone merged 4 commits intoRustPython:mainfrom
youknowone:os-fix

youknowone commented Feb 1, 2026 •

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github-actions bot commented Feb 1, 2026

📦 Library Dependencies

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youknowone commented Feb 1, 2026 •

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