Issues

• Test chineseYearlessBirthdays() performance regressed with foundation_swift_chinese_calendar_feature_enabled on

  bug
  swiftlang/swift-foundation#2285 · Filter by author itingliu opened on Oct 5, 2026
  1

• Decimal can round to the wrong adjacent value near its significand limit

  bug
  swiftlang/swift-foundation#2283 · Filter by author xwu opened on Oct 5, 2026

• Add LocalizedStringResource to swift-foundation (cross-platform availability)

  enhancement
  swiftlang/swift-foundation#2280 · Filter by author VictorPuga opened on Oct 4, 2026
  1

• XDG search paths resolve under /home when HOME is unset, disagreeing with homeDirectoryForCurrentUser

  swiftlang/swift-foundation#2252 · Filter by author sean-rowe opened on Sep 21, 2026
  1

• [Windows] TimeZone.current still returns GMT on Swift 6.3.2/6.4.0 despite #966 being closed as completed

  bug
  swiftlang/swift-foundation#2244 · Filter by author k-ngt opened on Sep 17, 2026
  

• [GLD Serializer Benchmark] Swift Foundation.PropertyListEncoder Foundation — spec compliance misses

  swiftlang/swift-foundation#2239 · Filter by author leo-gan opened on Sep 14, 2026

• [GLD Serializer Benchmark] Swift Foundation.JSONEncoder Foundation — spec compliance misses

  swiftlang/swift-foundation#2238 · Filter by author leo-gan opened on Sep 14, 2026

• Calendar.RecurrenceRule: yearly rule returns dates outside the months it was restricted to

  swiftlang/swift-foundation#2224 · Filter by author dmonagle opened on Sep 4, 2026
  1

• [New Codable] GrowableEncodingBytes deinit causes infinite recursion in Embedded Release

  bugnew-codable
  swiftlang/swift-foundation#2193 · Filter by author sliemeobn opened on Aug 20, 2026
  1

  

• Cannot build benchmark on a second try

  bug
  swiftlang/swift-foundation#2178 · Filter by author itingliu opened on Aug 13, 2026
  4

• Version windows libraries

  windows
  Task

  swiftlang/swift-foundation#2124 · Filter by author compnerd opened on Jul 21, 2026

• There should be an editorconfig file

  swiftlang/swift-foundation#2119 · Filter by author itingliu opened on Jul 17, 2026

• .systemFileNumber provided by FileManager.attributesOfItem is not correct on Windows

  bug
  swiftlang/swift-foundation#2107 · Filter by author Star-Lord-PHB opened on Jul 14, 2026
  

• URL.resourceValues crashed with larger file (2GB+) on Windows

  bug
  swiftlang/swift-foundation#2096 · Filter by author rayman-zhao opened on Jul 10, 2026
  

• Atomic writing should use FILE_RENAME_IGNORE_READONLY_ATTRIBUTE instead of manual unsetting

  bugwindows
  swiftlang/swift-foundation#2078 · Filter by author jmschonfeld opened on Jul 2, 2026
  1

  

• [New Codable] NewCodable runtime fails to build with swift-DEVELOPMENT-SNAPSHOT-2026-06-24-a

  bugnew-codable
  swiftlang/swift-foundation#2074 · Filter by author YeoSeongil opened on Jul 2, 2026
  2

• ProgressManager: concurrent observation does not work correctly

  bug
  swiftlang/swift-foundation#2053 · Filter by author itingliu opened on Jun 22, 2026
  3

  

• Support for "local" dates and times

  enhancement
  swiftlang/swift-foundation#2002 · Filter by author FranzBusch opened on May 27, 2026
  3

• Consider using var default values as replacement for CodableDefault

  enhancementnew-codable
  swiftlang/swift-foundation#2001 · Filter by author kperryua opened on May 26, 2026
  3

• Consider runtime-specified value "template" value for missing fields (or patching)

  enhancementnew-codable
  swiftlang/swift-foundation#2000 · Filter by author kperryua opened on May 26, 2026

• Lazy, ~Escapable decoder/enumerator type (JSON)

  enhancementnew-codable
  Feature

  swiftlang/swift-foundation#1914 · Filter by author kperryua opened on Apr 16, 2026

• Support the new Saudi riyal symbol with formatter API

  enhancement
  swiftlang/swift-foundation#1911 · Filter by author 0xifarouk opened on Apr 16, 2026
  2

• FileManager: Support setting .creationDate where possible

  bug
  swiftlang/swift-foundation#1906 · Filter by author WFT opened on Apr 15, 2026

• Thread safety issue in FoundationEssentials.Calendar

  bug
  swiftlang/swift-foundation#1886 · Filter by author TwirlySeal opened on Apr 8, 2026
  2

  

• Improved new-codable JSON support for large integers masquerading as floating points.

  bugnew-codable
  swiftlang/swift-foundation#1863 · Filter by author kperryua opened on Mar 30, 2026
  4