<span class="f1 text-normal markdown-title prc-Text-Text-9mHv3" data-component="Text">Update maintenance - # 269

What's Changed

Enhancements

Add mirror and mirror-token inputs for custom Python distribution sources by @luhenry in #1302
Improve error message clarity by @v-lmvysakh in #1351

Dependency Upgrade

Upgrade browserslist from 4.28.2 to 4.28.9 by @dependabot in #1353
Upgrade @typescript-eslint/parser from 8.62.0 to 8.70.0 by @dependabot in #1343
Upgrade eslint-plugin-jest from 29.15.2 to 29.16.6 by @dependabot in #1342
Upgrade @vercel/ncc from 0.44.0 to 0.45.0 by @dependabot in #1357
Upgrade @types/semver from 7.7.1 to 7.8.0 by @dependabot in #1359
Upgrade undici from 6.28.0 to 6.29.0 by @dependabot in #1364
Upgrade ts-jest from 29.4.11 to 29.4.14 by @dependabot in #1361
Upgrade brace-expansion from 5.0.9 to 5.0.12 by @dependabot in #1365
Upgrade prettier from 3.8.4 to 3.9.9 and package.json from 7.0.0 to 7.1.0 by @dependabot in #1363
Upgrade @typescript-eslint/eslint-plugin from 8.62.0 to 8.71.1 by @dependabot in #1369
Upgrade actions/checkout from 7.0.0 to 7.0.1 by @dependabot in #1345
Upgrade cache to 6.3.0 by @v-HarithaVattikuti in #1370
Resolve Basic Validation audit failures by @v-HarithaVattikuti in #1347
Resolve npm audit failures by @v-HarithaVattikuti in #1350

New Contributors

@luhenry made their first contribution in #1302

Full Changelog: actions/setup-python@v7.0.0...v7.1.0

psf/black (black)

`v26.10.1`

Highlights

This release fixes a security issue in Black's bundled GitHub Action. Repositories that
use the action are encouraged to update to the latest version of Black immediately. This
update is received automatically when using psf/black@stable, and is independent of
the version of Black installed by the action.

When the GitHub Action reads version specifiers from tool.black.required-version, it
now only accepts released versions of Black, as it already did for black requirements
in dependency lists. Other values, such as URL references, are now rejected. This issue
has been registered as GHSA-cg8m-r9f2-5wm2; a CVE identifier is pending.

Stable style

Fix a long Jupyter notebook assignment magic (for example x = !ls -la) being wrapped
in parentheses, which IPython can no longer run; such cells are now left unchanged
(#5481)
Keep repeated lines outside the selected --line-ranges unchanged (#5436)
Fix --line-ranges formatting lines that follow a statement when formatting joins or
re-indents that statement (#5484)
Fix --line-ranges crashing with an internal error when an unselected statement has a
# fmt: skip comment on the last line before a closing bracket (#5477)
Prevent moving an encoding declaration (for example # -*- coding: latin-1 -*-) onto
the first two lines of a file (#5487)
Fix adding an extra trailing blank line inside a multi-line module docstring when its
last line is near the line length limit (#5494)
Preserve blank lines between imports and unselected statements when using
--line-ranges, and ensure a blank line is added between an unselected import and a
newly formatted statement (#5493, #5649)
Keep the parentheses around a walrus that is the only item in a set (for example
{(x := f())}) when targeting Python 3.9 or older, since Python 3.8 and 3.9.0 can't
parse it without them (#5502)

Preview style

Do not split short expressions on delimiters (such as binary operators, comparisons,
or comprehensions) inside brackets when preceded by a standalone comment (#5455)
Fix the unstable string_processing feature removing backslash-newline sequences from
raw strings, which changed their value (#5482)
Avoid adding unnecessary parentheses around unbreakable right-hand side expressions in
assignments (such as annotated assignments or subscript targets) (#5473)
Parenthesize expressions with parameter comments when they exceed the line length
under --preview (#5442)
Fix wrap_long_dict_values_in_parens dropping the parentheses around a right-hand
side that contains a dictionary, leaving a line over the length limit (#5492)
Fix the unstable string_processing feature adding a space after * or ** in a PEP
695 type parameter (* Ts = ...) when it splits a string in the parameter's default
(#5504)
Avoid unnecessary line splits of trailers (such as indexing/subscripts) when an
earlier bracket split exceeds the line length only due to a trailing comment (#5498)

Configuration

Add --cache-dir to configure the cache directory from the command line (#5433)
Don't cache a file as formatted after formatting or checking it with --line-ranges,
which made a later full black --check pass and black skip the unformatted lines
(#5476)
Respect a .gitignore that starts with a UTF-8 byte order mark. The mark became part
of the first pattern, so that pattern never matched and Black formatted files that git
ignores (#5497)

Performance

Avoid quadratic runtime when splitting very long lines with many trailing bracket
pairs (such as consecutive subscripts) (#5475)

Integrations

Fix the GitHub Action crashing on dependency-group includes when use_pyproject is
enabled (#5479)
When the GitHub Action reads version specifiers from tool.black.required-version, it
now only accepts released versions of Black, as it already did for black
requirements in dependency lists. Other values, such as URL references, are now
rejected. (#5510)

pallets/click (click)

`v8.5.1`

Released 2026-11-09

Fix copy.deepcopy() and pickle on a Parameter, Option or Command. {pr}3805
A KeyboardInterrupt arriving while Command.main() reports an abort or an error,
or while it exits, no longer escapes as an unhandled traceback. The command still
exits with the intended code; only the message may be lost. {issue}3802
Add {meth}Option.get_help_spec, which returns the option's left help
column even when the option is hidden. {meth}Option.get_help_record still
returns None for hidden options, so help screens are unchanged. {pr}3821
The Positional arguments help section lists every argument of the command,
not only the documented ones. An argument with no help gets an empty
description, the same way an option with no help does. {pr}3860
{meth}Argument.get_help_record always returns a tuple. It used to return
None for an argument with no help. {pr}3860
Document which types are inferred from default, and what an unrecognized
type callable does to a command-line value. {issue}3036 {pr}3808
path_type narrows the converted value's type for convert and prompt.
{issue}3822 {pr}3858
{class}Parameter accepts a new help argument and {class}Option and {class}Argument
inherits it. {meth}Parameter.to_info_dict now reports help for every kind of parameter.
{pr}3861
A command's short help no longer stops at an abbreviation such as vs. or e.g.
inside the first sentence. A period ends the sentence only when it closes the text
or the next word does not start in lowercase. {pr}3865
With show_envvar=True, an option's error message now prints all variables of an
envvar sequence instead of the repr of the sequence. {pr}3884
An empty envvar, such as [] or "", shows the same help and error message as
no envvar when show_envvar=True. The help screen used to show [env var: ].
{pr}3884
Align command's deprecated help text to options and arguments: do not translate the
command's own help text, only the (DEPRECATED) label. {pr}3901

pypa/distlib (distlib)

`v0.4.4`

tox-dev/filelock (filelock)

`v4.2.9`

Bug fixes

ReadWriteLock, SoftReadWriteLock and their async wrappers now raise TypeError for a blocking that is not a bool, in the constructor and on acquire, as FileLock already does. Before, blocking=0 waited out the full timeout on a contended ReadWriteLock while blocking=False failed at once, and a truthy value such as "false" turned a single attempt into a blocking wait (#908) by @abhishekcpp007 and @gaborbernat.

New Contributors

@abhishekcpp007 made their first contribution in #908

`v4.2.8`

Documentation

Clarify the platform-specific locking primitive and range used by descriptor locks, and correct the guidance on interoperating with byte-range lock protocols such as conda's repodata lock (#905) by @boyfeiyu.

New Contributors

@boyfeiyu made their first contribution in #905

`v4.2.7`

Bug fixes

A SoftFileLease reclaims a dead holder's lease marker even when that holder published another lease_duration. It used to raise LeaseSettingsMismatch on every attempt instead, so after a holder crashed and its peers restarted with a changed duration the lock stayed wedged until force_break(). A live holder with another duration still raises (#900) by @dxbjavid and @gaborbernat.

PyPI release

Full Changelog

`v4.2.6`

Bug fixes

Fix a race in SoftFileLock, MarkerSoftFileLock and SoftFileLease when three or more contenders reclaim a dead marker. The race could strand a live holder's marker under a break name, leaving the lock unusable or admitting a second holder. Contenders now recheck the marker before exchanging names and unwind nested exchanges in order. If the filesystem refuses a return exchange, the contender leaves its marker at the lock path for later recovery (#899) by @dxbjavid and @gaborbernat.

PyPI release

Full Changelog

`v4.2.5`

Bug fixes

acquire and acquire raise TypeError for a blocking that is not a bool, as the constructor and the blocking setter already do. A truthy value such as the string "false" used to count as True, so a call meant as a single attempt waited for the instance's timeout, and without a limit at the default -1 (#870) by @simpleqt and @gaborbernat.
A SoftFileLock acquisition whose first read of its new marker's identity failed reads it again before rolling back. On Windows the rollback could otherwise not recognize the marker it had created, and the empty marker it left blocked the path for every later acquisition, since no contender breaks an empty marker (#869) by @simpleqt and @gaborbernat.
A fork() child of a process holding a SoftFileLease starts from an unheld claim. It used to inherit the parent's token, last compromise and heartbeat, so token and compromise reported a claim the child never held while is_locked reported it unheld (#868) by @dxbjavid and @gaborbernat.
A nested acquire of a held FileLock or SoftFileLock no longer creates the lock file's parent directory. After a rename of that directory during the hold, the nested acquire recreated the old name, and when a file had taken the name it raised FileExistsError and left the hold's recursion count incremented (#878) by @0x5t4l1n and @gaborbernat.
Fix ReadWriteLock failing every acquire with "link directory ... was replaced while opening" in a group-writable directory whose inherited ACL, such as an NFSv4 one on ZFS, opens the link directory to the group. The lock now closes the empty link directory to its owner, and where the filesystem refuses that, such as ZFS with aclmode=restricted, it names the directory to make writable by its owner only (#898) by @gaborbernat.
Fix SoftFileLock, MarkerSoftFileLock and SoftFileLease raising OverflowError out of acquire(), or never reclaiming a dead holder's lock, when a stranded restore claim beside the lock names a process number outside 1..2**31-1 or spells it in non-ASCII digits. Such a claim is now ignored, as no filelock writes one (#871) by @dxbjavid and @gaborbernat.
Fix soft locks on Windows keeping the marker of a holder that has exited while another process still holds a handle to it, such as a parent's subprocess.Popen after wait() or multiprocessing.Process after join(). Acquiring such a lock with the default timeout=-1 waited forever (#874) by @nk-batman21.
Fix the read-only reopen of a lock file this account cannot write resolving a relative path against the working directory of the moment. A chdir between the refused O_RDWR open and the reopen made the acquisition wait on a file that is not there, or probe one in another directory. The reopen now uses the path the acquisition pinned (#889) by @dxbjavid and @gaborbernat.
Handle EMLINK, the error FreeBSD reports when a no-follow open refuses a symlink, in a soft reader/writer lock's protocol tree, so heartbeat reports lost ownership there rather than a transient refresh error (#866) by @pacocartones and @gaborbernat.
Resolving ReadWriteLock or AsyncReadWriteLock raises the ImportError when a module other than Python's sqlite3 is missing, as in a frozen application that left out a filelock submodule. The names are None only without SQLite (#880) by @pintu544 and @gaborbernat.

Documentation

The lock-probing recipe in the how-to guide probes with blocking=False instead of a tiny timeout (#873) by @tongwentao and @gaborbernat.

Packaging

Releases now run on the shared tox-dev/github-workflows pipeline, with a locked release toolchain and generated GitHub Release notes (#885) by @gaborbernat.

New Contributors

@simpleqt made their first contribution in #869
@KennyMcSimpson made their first contribution in #875
@0x5t4l1n made their first contribution in #878
@tongwentao made their first contribution in #873
@pacocartones made their first contribution in #866
@nk-batman21 made their first contribution in #874
@pintu544 made their first contribution in #880
@00200200 made their first contribution in #877

PyPI release

Full Changelog

`v4.2.4`

`v4.2.3`

Bug fixes

Creating a lock on a Python 3.15 interpreter without types.LazyImportType no longer triggers AttributeError at exit. #861 by @gaborbernat.
Handle EFTYPE when a no-follow open refuses a symlink in a soft reader/writer lock's protocol tree, so heartbeat reports lost ownership rather than a transient refresh error. #859 by @edsonsims.

New Contributors

@edsonsims made their first contribution in #859

`v4.2.2`

Bug fixes

Fix a lock on a relative path that stayed held after a later with lock: ended, when an earlier acquire() had failed because the working directory no longer exists. That call still raises FileNotFoundError, and it now leaves the lock's hold count unchanged. #856 by @spicysharkco.

New Contributors

@spicysharkco made their first contribution in #856

`v4.2.1`

Security

This release fixes the following vulnerabilities:

CVE-2026-112940 (high): ReadWriteLock: SQLite reopens the lock database by name, so a planted symlink or journal file makes the lock user's process overwrite or unlink its own files.
CVE-2026-112906 (medium): SoftFileLock evicts a fresh lock file whose watched age another local user's pre-dated file passed on through inode reuse.
CVE-2026-112908 (medium): StrictSoftFileLock creates its claim directories without the lock mode, so another local user with a write bit on them can end a live hold.
CVE-2026-112909 (medium): UnixFileLock truncates and chmods any regular file another user renames or hard-links onto the lock path.
CVE-2026-112910 (medium): WindowsFileLock ignores mode: a 0o600 lock file and the ReadWriteLock database inherit the directory ACL.
CVE-2026-112911 (medium): StrictSoftFileLock and SoftReadWriteLock adopt a protocol directory another user created first, losing mutual exclusion.
CVE-2026-112914 (medium): SoftFileLock stale-break restore follows a swapped-in symbolic link and hard-links a file of the user running the lock into the lock directory.
CVE-2026-112915 (medium): ReadWriteLock: a crafted lock database makes every acquire stall or hang regardless of timeout.
CVE-2026-112934 (medium): SoftReadWriteLock holder refresh writes through a hard link and hangs on a named pipe that another local user renames over its record.
CVE-2026-112935 (medium): SoftFileLock stale-lock break removes a live lock file on a reused inode number and admits two holders.
CVE-2026-112937 (medium): ReadWriteLock on the hard-link route deletes any directory another user renames onto its .filelock-* link directory name.
CVE-2026-112938 (medium): StrictSoftFileLock follows a symbolic link swapped in at .filelock and creates claim files in a directory another local user chooses.
CVE-2026-112939 (medium): SoftFileLock removes a live holder's marker when another user forges the PID in a writable marker.
CVE-2026-112907 (low): On Windows an oplock on a soft lock's marker holds SoftFileLock.acquire() past its timeout and blocks the stale break.
CVE-2026-112912 (low): Symlink swap during SoftFileLock's writability check leaks whether a path exists and is writable by the lock taker.
CVE-2026-112913 (low): ReadWriteLock on Windows acts on SQLite side files another local user places beside its database.
CVE-2026-112941 (low): SoftReadWriteLock follows a lock tree swapped in after its first acquire and writes lock records into directories of the user running the lock.

Bug fixes

On a singleton wrapper, AsyncReadWriteLock.close() and AsyncSoftReadWriteLock.close() end only the holds that tasks acquired through that wrapper. A reader that arrives during close() gets the closed error instead of joining the ending hold. After synchronous code closes or force-releases the shared lock, the wrappers refuse to admit readers into the ended hold, and close() on such a wrapper returns. Closing one wrapper no longer ends a task's nested hold taken through another wrapper on the same path. #832 by @gaborbernat.
ReadWriteLock locks again after a release() that an exception from a signal handler interrupted. The async read-write wrappers stop admitting readers into such a level. The async read-write locks forget a hold whose backend release failed after the backend let go, and they free the memory of each acquire that times out or is canceled. AsyncFileLock returns from release() after a few hundred acquires gave up behind a waiting one. An exception from a signal handler delivered while an AsyncFileLock call joins its queue no longer blocks every later call on that lock. #833 by @gaborbernat.
Fix ReadWriteLock acting on -journal, -wal or -shm files another process puts beside its database: a write could land in another file, a reader could get in beside a writer, and an acquire could fail. SQLite now opens the database by name only in a directory no other account can write, and through a private hard link elsewhere. On Windows the directory's access control list decides. Where hard links are unavailable, keep the database in a directory other accounts cannot write, such as one under %LOCALAPPDATA%. The lock removes link directories through a checked descriptor rather than by name, reads a link directory's name only when the locking account owns it, and leaves alone a directory with other content renamed onto a link directory's name. A database whose schema takes more than a few kilobytes to load raises ValueError instead of running past the acquire timeout. #834 by @gaborbernat.
Fix five bugs in opening the lock file. UnixFileLock no longer truncates a file it did not create, such as one renamed to the lock path, and no longer applies mode to it. An on_acquired hook that writes holder metadata now truncates the file itself. A lease (Linux) or an oplock (Windows) on the lock file or a soft lock's marker no longer holds acquire() past its timeout or blocking=False, and an oplock no longer holds release(); ReadWriteLock on Windows waits for its timeout and raises Timeout. On Windows, a mode without group and other bits, such as 0o600, now creates the lock file with an owner-only permission list; the ReadWriteLock database gets the same. The soft locks' writability check no longer follows a symlink swapped in at the lock path. On a filesystem without flock, a contender from another account now waits on a marker it cannot write instead of raising PermissionError. #835 by @gaborbernat.
Fix SoftFileLock, MarkerSoftFileLock and SoftFileLease removing a live holder's marker in three cases: the holder and the contender run in Linux time namespaces with different boottime offsets; only one of them can read the boot id; a process other than the owner rewrote the marker. Soft markers no longer carry group or other write bits. A process name containing a carriage return or another line separator no longer makes the stale check raise ValueError. When /proc/self/ns/time exists but cannot be read, the stale check no longer compares start times and keeps the marker. #836 by @gaborbernat.
The async read-write locks record their hold under a task owner, so synchronous code on the executor thread that took the hold can no longer re-enter or release it. AsyncSoftReadWriteLock gives back one level on release, so synchronous readers of a shared singleton keep theirs. SoftReadWriteLock tracks read levels per thread: release() from a thread that holds none raises RuntimeError. After its heartbeat recorded a lost hold, it refuses new acquires until that hold is released. #838 by @gaborbernat.
StrictSoftFileLock creates <path>.filelock and its claims directory with the lock's mode and sets the sticky bit (a directory flag that lets only a file's owner remove it) on both. On the next acquisition it narrows a directory it owns that an earlier release created wider; it leaves a directory of another account as it is, so remove such leftovers by hand. It reaches claims through a descriptor opened without following symlinks; on Windows it holds both directories open and refuses a junction (a directory that points at another directory). Under a sticky parent such as /tmp it refuses a coordination directory of another account, as SoftReadWriteLock does for <path>.rw. One read grace now covers a whole claim scan, a failed claim cleanup no longer leaves the sentinel descriptor open, and a non-regular node at a sentinel private-record name raises SoftFileLockProtocolError. On Windows, contenders read claims without blocking their owner's unlink. #839 by @gaborbernat.
Fix a lock reporting a hold the OS had dropped after a signal handler raised during acquire or release. A release that a signal handler cuts short after it has started now completes before the error propagates. A handler that acquires the lock its own thread is releasing now gets RuntimeError instead of a hold that stays held. The singleton cache no longer hands out an is_singleton=True lock or a ReadWriteLock whose finalizer is running, which released the new holder's lock. A signal during os.fork() no longer leaves the other threads blocked in their next lock call, and a fork from another thread no longer waits for a ReadWriteLock acquire on a busy database. #840 by @gaborbernat.
Fix a lock on a relative path locking a file in the directory the process changed to while the lock waited, and leaving its marker behind on release after such a change. The path resolved when an acquisition starts stays in use until the hold ends. An is_singleton=True lookup no longer returns a cached lock whose relative path now resolves to another file; a held lock still matches the file it holds. A rename of the lock's directory during a hold no longer leaves the marker behind or reports a false lease compromise, and a waiter no longer creates a second lock file in a directory that was renamed away. #841 by @gaborbernat.
SoftReadWriteLock reaches its records through descriptors of <path>.rw and gen or holders opened without following symlinks. On Windows it holds those directories open and refuses a junction (a directory that points at another directory). A tree swapped in after an earlier acquire therefore cannot redirect them. Its heartbeat rewrites a holder record only when the name still leads to the file it created, and does not block on a FIFO (a named pipe). A heartbeat that finds <path>.rw replaced by a symlink or junction reports the hold lost instead of ending the heartbeat thread. A live lock object repeats the ownership check whenever the tree it opens is not the one it prepared. #842 by @gaborbernat.
Fix SoftFileLock, MarkerSoftFileLock and SoftFileLease removing or displacing a live holder's marker in five cases. ext4 gave a freed inode number to the next marker. A stalled FileLock removed its ENOSYS placeholder after a peer replaced it. A failed acquire cleaned up after a successor took the path. A stale break left the lock path empty while it checked the marker it had moved. A lifetime break judged a marker by a reused inode number. On Linux and macOS a stale marker now changes hands in one atomic exchange. On other platforms without one, except Windows, including NFS and SMB, the marker stays in place and waits for timeout or break_lock(). Restoring a marker no longer follows a symlink found under the break name. A holder that releases while a peer's exchange has its marker aside leaves a record no lock parses, so the put-back lands a marker that ages out. A lease heartbeat that finds another file at the lock path once, while a peer's break has its marker aside, waits for the next refresh before it reports a compromise. A contender that finds a dead breaker's marker puts back the marker that breaker left under its break name. A marker is the breaker's own only when it names the breaker's process on this host; the same process number on another host is a holder. A contender takes a stranded marker under a name of its own before it puts the marker back, so two contenders no longer reverse each other's exchange and remove the live holder's marker. A claim left behind by a failed put-back is retried on the next poll. #843 by @gaborbernat.
Canceling an AsyncReadWriteLock or AsyncSoftReadWriteLock acquire that waits for another process now stops the wait and raises the cancellation. It used to wait until that process released, or raise Timeout. A thread_local=True AsyncFileLock that threads with their own event loops share no longer deadlocks when one thread waits for the lock while another holds it. #844 by @gaborbernat.
SoftReadWriteLock refuses a commit that lands a whole retention window behind the log, so two committers stalled at adjacent generations can no longer admit a second writer. Its stale check samples the clock before it reads a holder record, so a pause between the two no longer counts as time the record stayed unchanged. #845 by @gaborbernat.
Fix a SoftFileLock contender evicting an empty marker after two seconds while its owner held the lock. The owner is a SoftFileLock before 3.22, which writes nothing into its marker, or a current one still writing its record. An empty marker now reads as held, and timeout, lifetime or break_lock() clears it. A contender that finds an empty marker a dead breaker left aside puts it back instead of removing it. #846 by @gaborbernat.
Fix ReadWriteLock on Windows acting on -journal and -wal files another account places beside its database: an acquire could fail with OperationalError, or SQLite could replay the journal and delete the file it names. The lock now reads the database directory's access control list. Where an account other than the locking account, SYSTEM and Administrators can add or remove names, SQLite opens a hard link inside a directory only those accounts can write. A filesystem without hard links raises OSError. #854 by @gaborbernat.
Fix SoftReadWriteLock subclasses sharing singleton instances with the base class or sibling subclasses. Each concrete class now keeps its own cache and construction guard, including after fork, while preserving cooperative class-definition keywords. #855 by @AryanRG.

New Contributors

@AryanRG made their first contribution in #855

`v4.2.0`