0.5.10 (2026-01-24)

We’re happy to announce the release of Scala Native 0.5.10.

Supported Scala versions

Scala Binary Version	Supported Scala Versions
2.12	2.12.17 … 2.12.21
2.13	2.13.9 … 2.13.18
3	3.1.2 … 3.1.3 3.2.0 … 3.2.2 3.3.0 … 3.3.7 LTS 3.4.0 … 3.4.3 3.5.0 … 3.5.2 3.6.2 … 3.6.4 3.7.0 … 3.7.4 3.8.0 … 3.8.1

Upon release of new Scala version (stable, or Scala 3 RC) version dependent artifacts would be published without a new release.

Commits since last release	179
Merged PRs	169
Contributors	9

Contributors

Big thanks to everybody who contributed to this release or reported an issue!

$ git shortlog -sn --no-merges v0.5.9..v0.5.10
    95	Albert Meltzer
    28	LeeTibbert
    27	Wojciech Mazur
    16	Scala Steward
     4	Corey O'Connor
     4	dependabot[bot]
     1	Ali Rashid
     1	Eric K Richardson
     1	Lorenzo Gabriele

Merged PRs

v0.5.10 (2026-01-24)

Full Changelog

Merged pull requests:

Scala Native Compiler Plugin

• Support Scala 3.8 new lazy vals and stdlib -Yexplicit-nulls #4531 (WojciechMazur)

• When testing isExtern check original owner instead of current one #4730 (WojciechMazur)

• Fix #4747: genIf incorrectly forces Unit type when only one branch is Unit #4748 (arashi01)

Scala Native runtime

• Matcher: do not copy strings, append as sequence #4653 (kitbellew)

• Matcher: fix bugs in appendReplacement #4654 (kitbellew)

• Matcher: pass region as subsequence to RE2 #4199 (kitbellew)

• unsafe: remove extra memory copy in toCXxxString #4661 (kitbellew)

• Ptr: DRY, reuse shared methods, avoid boxing #4688 (kitbellew)

• StackTrace: avoid NPE in early initialization #4698 (kitbellew)

• [GC] Refactor GC logging #4736 (WojciechMazur)

• [GC:immix/commix] Detect and crash on GC deadlock #4739 (WojciechMazur)

• Fix materialization of lazilly collected stack traces #4733 (WojciechMazur)

• Inline loadModule but not all of it #4735 (coreyoconnor)

Scala Native Toolchain

• Emphasize toolchain multithread ‘detect’ #4718 (LeeTibbert)

• Avoid repeat O(n) descent into insts list #4753 (coreyoconnor)

• Use vector for initial instruction toSeq #4754 (coreyoconnor)

Java Standard Library

• Fix porting glitches, including self deadlock, in javalib ConcurrentHashMap #4522 (LeeTibbert)

• Make javalib linux_sched.c robust to _GNU_SOURCE already being defined #4523 (LeeTibbert)

• Fix Scala 2.* NPE in javalib ConcurrentHashMap #4527 (LeeTibbert)

• ProcessBuilder: centralize, simplify getting envp #4546 (kitbellew)

• ProcessBuilder: user.dir is a property, not env #4557 (kitbellew)

• ProcessBuilder: implement JDK9 Redirect.DISCARD #4570 (kitbellew)

• UnixProcessGen1: DRY use UnixProcessGen2.forkChild #4541 (kitbellew)

• UnixProcessGen1: remove unused methods #4563 (kitbellew)

• UnixProcessGen1: monitor in GenericProcessWatcher #4576 (kitbellew)

• UnixProcessGen1: catch TimeoutException in waitFor #4617 (kitbellew)

• UnixProcessGen2: re-use binaryPaths in spawnChild #4545 (kitbellew)

• UnixProcessGen2: add createPipe, dup2, dup2Spawn #4542 (kitbellew)

• UnixProcessGen2: don’t copy stderr on redirect #4543 (kitbellew)

• UnixProcessGen2: don’t create unused pipes, close all unused descriptors #4550 (kitbellew)

• UnixProcessGen2: save pidfd in the Handle #4566 (kitbellew)

• UnixProcessGen2: make sure to close pipes on error #4575 (kitbellew)

• UnixProcessGen2: retry fork()/spawn() on EAGAIN #4623 (kitbellew)

• UnixProcessGen2: use atomic to close pidfd #4644 (kitbellew)

• UnixProcessGen2: simplify createPipe with alloc #4549 (kitbellew)

• UnixProcessGen2: posix_spawn_file_actions_addopen #4554 (kitbellew)

• UnixProcessGenX: remove unused ctor, inline other #4547 (kitbellew)

• UnixProcess: don’t keep pipe fd pairs as fields #4548 (kitbellew)

• UnixProcessXxx: refactoring (waitpid, imports) #4584 (kitbellew)

• UnixProcess: add throwOnErrorRetryEINTR #4616 (kitbellew)

• WindowsProcess: provide _pid directly in ctor #4582 (kitbellew)

• WindowsProcessHandle: use ProcessExitChecker #4681 (kitbellew)

• ProcessExitChecker: split Factory, change Single #4656 (kitbellew)

• GenericProcess: drain/close each stream separately #4540 (kitbellew)

• GenericProcess: no synchronized, ignore reaped #4588 (kitbellew)

• GenericProcessWatcher: add reapSomeProcesses #4583 (kitbellew)

• GenericProcessWatcher: avoid missing a new process #4646 (kitbellew)

• GenericProcessWatcher: catch exceptions reaping #4647 (kitbellew)

• GenericProcessWatcher: move most to nested object #4643 (kitbellew)

• PipeIO: do not “check if process exited” #4539 (kitbellew)

• PipeIO: NullInput must return -1 in read() #4564 (kitbellew)

• PipeIO: auto-close input stream on EOF #4565 (kitbellew)

• PipeIO: to read, check if src matches file stream #4572 (kitbellew)

• PipeIO: use InputStream, complexity to FileChannel #4574 (kitbellew)

• BsdOsSpecific: fix bug in kevent struct ident/data #4601 (kitbellew)

• FileDescriptor: simplify sync() method #4659 (kitbellew)

• FileDescriptor: use atomic file handle #4658 (kitbellew)

• FileDescriptor: use AnyVal, close only if valid #4645 (kitbellew)

• FileChannelImpl: make available() non-negative #4589 (kitbellew)

• Channel close improvements #4648 (LeeTibbert)

• ExitChecker: add lnx/bsd single-pid exit watchers #4600 (kitbellew)

• ExitChecker: add lnx/bsd multi-pid exit watchers #4631 (kitbellew)

• WeakReference: fix JDK compliance w/ clear/enqueue #4672 (kitbellew)

• WeakReferenceRegistry: fix bugs, add consistency #4674 (kitbellew)

• WeakReferenceRegistry: move thread inside object #4690 (kitbellew)

• Cleaner: implement using WeakReferenceRegistry #4664 (kitbellew)

• Cleaner: define own subclass of WeakReference #4684 (kitbellew)

• Cleaner: use own thread, not shared ForkJoinPool #4685 (kitbellew)

• InputStream: refactor read() #4686 (kitbellew)

• InputStream: refactor readNBytes, readSmallN #4687 (kitbellew)

• InputStream: consolidate bounds check in read #4702 (kitbellew)

• InputStream: ArrayList, not ConcurrentLinkedQueue #4697 (kitbellew)

• InputStream: refactor readLargeN #4689 (kitbellew)

• ReferenceQueue: timeout == 0 should be infinite #4691 (kitbellew)

• ReferenceQueue: add dequeue, use in poll, remove #4693 (kitbellew)

• ReferenceQueue: keep as Reference[_ <: T] #4692 (kitbellew)

• ReferenceQueue: use java ArrayDeque vs scala Queue #4701 (kitbellew)

• Check posixlib UnixProcessFactory unistd.chdir(); update comments #4703 (LeeTibbert)

• [javalib] Ensure Process.waitFor links when multithreading is disabled #4732 (WojciechMazur)

• [javalib] Fix semantics of java.util.concurrent.atomic types #4734 (WojciechMazur)

• [javalib] Fix #4722: Eliminate PosixThread maxSeconds & re-factor time handling #4738 (LeeTibbert)

• javalib UnixProcessFactory now favors posix_spawn when available #4712 (LeeTibbert)

• Fix #4742: javalib *Stream#filter spliterator characteristics now match JVM #4744 (LeeTibbert)

• Fix #4743: javalib *Stream#distinct spliterator characteristics now match JVM. #4746 (LeeTibbert)

• Fix #4740: Port Scala.js ‘Fix modPow2Inverse used by BigInteger.modPow’ #4749 (LeeTibbert)

POSIX bindings

• Update posixlib spawn.scala to Open Group Issue 8, 2024 #4567 (LeeTibbert)

• posix/{epoll,eventfd}: define epoll_xxx, eventfd #4624 (kitbellew)

• posix/kevent: move kqueue/kevent definitions #4625 (kitbellew)

• posix/{ppoll,pidfd}: move ppoll and pidfd to posix #4627 (kitbellew)

• posix/poll: change hardcoded constants to imported #4626 (kitbellew)

• posix/epoll: remove epoll_event, it’s invalid #4637 (kitbellew)

• posix/kevent: remove scala kevent type, use C-lang #4638 (kitbellew)

• mmap: expose the MAP_FAILED constant and use it #4665 (kitbellew)

• posixlib: implement MAP_ANON and MAP_ANONYMOUS constants #4671 (LeeTibbert)

• Fix #4143 termios Posix library does not work on Linux #4155 (ekrich)

• Add @blocking annotation to unistd chdir & fchdir #4696 (LeeTibbert)

• Three corrections to posixlib spawn; blocking and chdir argument #4711 (LeeTibbert)

C Standard Library bindings

• Add strErrNo = fromCString(strerror(errno)) #4585 (kitbellew)

• Implement and use two libc stdint fields #4606 (LeeTibbert)

• Add #if defined in windows time.c #4670 (lolgab)