v3.3.6

Compare Source

Highlights of the release

• REPL: Add REPL init script setting #​22206
• Update asm to patched 9.8.0 to support new JDK versions #​23004
• classfile reader: handle JDK 9+ constant types in constant pool #​19533
• REPL: Add back :silent command #​22248
• Scala 2 forward port: -Yprofile-trace #​19897

Other changes and fixes

Annotations

• Make sure symbols in annotation trees are fresh before pickling #​22002
• Fix Java parsing of annotations on qualified types #​21867
• Rename InlineCopier to ConservativeTreeCopier, use it in TypeMaps #​21941
• Consider all arguments in Annotations.refersToParamOf #​22001

Backend

• Flag class file collision as error #​19332
• Backend computes line number from source of position #​21763

CI

• In CI, use new standard scala/cla-checker action #​22203
• Cancel stale CI executions when CI is re-triggered in the same branch/PR #​21974
• Drop support for old experimental in community-build #​21729

Coverage

• Fix coverage serialization when encountering macro suspension #​22303

Dependencies

• Sbt 1.10.5 (was 1.9.9) #​20157
• Scala 2.13.16 (was .15) #​22386

Desugaring

• Fix #​22051: only trust the type application part for case class unapplies #​22099

Documentation

• Fix: typo in documentation for Tuple.zip #​22313
• Copyright 2025 #​22326
• Documentation only: update Example code linked to obsolete content in macros-spec.md #​22256
• Doc fix, removed repeated use of the word with #​21915
• Fix typos #​21913

Enums

• Add type parameters derived from enum to default param getters of enum cases #​22157

Extension Methods

• Add regression test for #​22320 #​22321
• Tweak ExtensionNullifiedByMember #​22268

Infrastructure

• Improve, document and group versioning code in Build.scala #​21837
• Fix: drop jackson-module-scala from CB #​22353
• Fix inductive-implicits benchmark #​22007
• Remove tests/pos-with-compiler-cc from VSCode ignored files #​22198
• Bump webrick from 1.8.2 to 1.9.1 in /docs/_spec #​22066
• Fix Windows OS detection in TraceNameManglingTest #​21937
• Don't warn for deprecated Thread.getId() calls in ChromeTrace #​21831
• Improvement: Remove workaround for Bloop and update docs #​21842
• Ensure ChromeTraceTest event timestamps are emitted in correct invervals #​21911
• Remove tests/pos-with-compiler-cc #​21956
• Shade scalajs.ir under dotty.tools #​21765

Implicits

• Rollback constraints in compareAppliedTypeParamRef #​22339
• Apply implicit conversion from derived Conversion instance defined as implicit rather than given #​21785

Imports

• Allow imports nested in packagings to shadow #​21539

Inline

• Fix inline reduction for CaseDef guards with asInstanceOf #​22305
• Avoid using the current denotation in NamedType.disambiguate #​21414

Linting

• Append instead of prepending import selectors for the current scope when collecting them in CheckUnused #​22314
• Allow discarding "Discarded non-Unit" warnings with : Unit #​21927
• Disallow open modifier on objects #​21922
• Only count associated files of direct members of package objects in dropStale #​22190

Metaprogramming

• Rethrow SuspendExceptions caught in CodeGen phase #​22009
• Extend compiletime.testing.typechecks with certain transform phases #​21185

Match Types

• Fix #​21841: Check more that an unapplySeq on a NonEmptyTuple is valid. #​22366
• Type avoidance in MT bound inference #​22142

Nullability

• Fix #​21619: Refactor NotNullInfo to record every reference which is retracted once. #​21624

Parser

• Fix: don't consider into as a soft-modifier #​21924
• Fix: Allow as as an infix type in non context bound types #​21849
• Undo patch of double-block apply #​21982

Pattern Matching

• (Re-)Drop inaccessible subclasses from refineUsingParent #​21930
• Fix #​21914: Don't project nested wildcard patterns to nullable #​21934
• Fix use of class terms in match analysis #​21848
• Fix provablyDisjoint handling enum constants with mixins #​21876
• Do not consider uninhabited constructors when performing exhaustive match checking #​21750

Pickling

• Avoid orphan param from default arg #​21824
• Make sure definition tree has the defined symbol #​21851

Presentation Compiler

• Use new infer expected type for singleton complations #​21421
• Fix presentation compiler testcases #​22253
• Fix match error in keyword completions #​22138
• Add test cases project for presentation compiler #​22101
• Improvement: Update mtags to 1.4.1 and backport remaining changes #​21859
• Backport changes for the presentation compiler from Metals #​21756

Quotes

• Fix tupleTypeFromSeq for XXL tuples #​21782
• Do not bring forward symbols created in transform and backend phases #​21865
• Fix #​20471: owners of top-level symbols in cached quoted code being incorrect #​21945
• Fix for macro annotation that resolves macro-based implicit crashing the compiler #​20353
• Allow macro annotations to recover from suspension #​21969

REPL

• REPL: JLine: follow recommendation to use JNI, not JNA; also JLine 3.27.1 (was 3.27.0) #​22205
• Fix #​9879: allow top-level opaque type definitions in REPL #​21753

Reflection

• Do not return java outline dummy constructor in primaryConstructor #​22104

Reporting

• Normalise the types for Type Mismatch Error (E007) #​22337
• Do not warn about expected missing positions in quotes.reflect.Symbol #​21677
• Add missing error messages to asserts in QuotesImpl #​21852
• Don't point to the compiler backlog when a compiler plugin phase crashes #​21887
• Nowarn extension matching nonpublic member #​21825
• Fix: better error messages when an enum derives from AnyVal #​22236

Scaladoc

• [ISSUE-#​19208] If scaladocs on file protocol don't do SPA routing. #​22013
• Fix scaladoc graph highlight background color in dark mode #​21814

SemanticDB

• Extract semanticDB for lifted definitions #​21856

Specification

• Align the spec to allow the marker #​22323
• Fix #​20271: Bring for comprehension spec up to date. #​21702
• Spec: Integrate the specification for match types. #​22164

Settings

• Limit exposure to ConcurrentModificationException when sys props are replaced or mutated #​22180

Tooling

• Connect the input to the compiler in sbt #​22336
• Ensure to escape characters before constructing JSON profile trace #​21872
• Fix: correctly print literal types in the refined printer #​22351

Transform

• Attempt to beta reduce only if parameters and arguments have same shape #​21970
• Fix enclosingClass from returning refinement classes #​21411
• Fix #​22226: Use classOf[BoxedUnit] for Unit array in ArrayConstructors. #​22238
• Fix typo in allTermArguments #​21836

Typer

• Fixes for isLegalPrefix change #​22241
• Resolve name when named imp is behind wild imps #​21888
• Do not crash when typing a closure with unknown type, since it can occur for erroneous input #​21178
• Allow autotupling if fn's param is a type param #​21741
• Fix ctx implicits under case unapplySeq #​21748
• Avoid using ExplainingTypeComparer in regular code #​21583
• Avoid erasure/preErasure issues around Any in transformIsInstanceOf #​21647
• Remove tvars introduced while testing normalizedCompatible #​21466

Miscellaneous

• Replace deprecated AnyRefMap #​22230

Contributors

Thank you to all the contributors who made this release possible 🎉

According to git shortlog -sn --no-merges 3.3.5..3.3.6-RC1 these are:

    63  Tomasz Godzik
    30  Dale Wijnand
    26  Wojciech Mazur
    20  noti0na1
    15  Hamza Remmal
    15  Matt Bovel
    10  Jan Chyb
     9  Kacper Korban
     6  Som Snytt
     4  Sébastien Doeraene
     3  HarrisL2
     3  Jamie Thompson
     3  Martin Odersky
     3  Seth Tisue
     3  kasiaMarek
     2  Friendseeker
     2  João Ferreira
     2  Kenji Yoshida
     2  Natsu Kagami
     2  Pascal Weisenburger
     2  dependabot[bot]
     1  Adrien Piquerez
     1  Alden Torres
     1  Alexander
     1  Georgi Krastev
     1  Guillaume Martres
     1  Jentsch
     1  Lunfu Zhong
     1  Mathias
     1  Michał Pałka
     1  Oleg Zenzin
     1  Oliver Bračevac
     1  friendseeker
     1  philippus
     1  tgodzik
     1  xiaoshihou

v3.3.5

Compare Source

Highlights of the release

• Use Scala 2.13.15 standard library #​21648
• Support JDK 23 #​20144
• Add the -Wall option that enables all warnings #​20577

Breaking changes

• Aligned -Wconf parsing order with Scala 2 semantics: -Wconf:x,y now means -Wconf:x -Wconf:y, with y overruling x, rather than the reverse to align with Scala 3.4+ and with user intuition #​21985

Other changes and fixes

Annotations

• Tighten java annot value parsing #​21650

Exports

• Re-use attachment in exportForwarders to handle ambiguous overloads #​21518
• Allow export statements in AnyVal #​21653

Extension Methods

• Make right assoc ext method fwd refs error #​21641

Inference

• Fix #​20521: Optimise caching for computing atoms and widened in OrTypes #​21223

Linting

• Add origin filter to WConf, DeprecationWarning #​21404
• CheckUnused checks type param annotations #​20549

Match Types

• Fix #​20897: Make Nothing ⋔ Nothing, as per spec. #​21241
• Always interpret underscores inside patterns as type bounds #​21718

Overloading

• Report only non-overridden unimplemented members #​21337

Parser

• Harden skip in Scanner #​21607
• SimplePattern errors should now be recovered as wildcard instead of unimplemented expr #​21438

Positions

• Fix trailing comma Ident's span #​20445

Presentation Compiler

• Fix autoimports with using directives #​21590
• Remove artificial CURSOR added to code in the completions #​20899
• Help implement Metals' infer expected type feature #​21390
• Weekly metals backport #​21343
• Change mock symbol search #​21296
• Fix: completions when parenthesis already provided #​21299
• Backport from metals #​21196
• Fix: don't add suffix if brackets already present #​21259

Quotes

• Handle suspension due to macro call in arbitrary phases #​21651
• Have a better error message when healing types #​21711
• Expr#show: Don't crash when the expression contains an unsupported type (like a SkolemType) #​20494
• Quotes type printing: take infix type modifier into account #​21726

Reporting

• Nicer error message in case a derived method has an explicit term param #​21332
• Add better error reporting for inlined non-immutable paths #​21639

Releases

• Add support for Chocolatey #​20534
• Add the merge commit hash to the icon's url #​21221
• Add sources of synthetic classes to sources jar #​20904

REPL

• Uppdate JLine to 3.27.0 (was 3.25.1) #​21752
• Allow JLine to fall back to a dumb terminal #​21330
• JLine: follow recommendation to use JNI, not JNA; also JLine 3.27.1 (was 3.27.0) #​22205

Runner

• Fix old scala runner to use correct JLine classpath #​22464
• Fix remaining JNA classpath entries in dist/bin/scaladoc* scripts #​22471

Scaladoc

• Only trim one newline when preprocessing the content of a markdown code snippet #​21519
• Bump Inkuire version to fix it for the new Scala versions #​21611
• Filter opaque modifier from object documentation #​21640

TASTy format

• Add child to parent in completion context #​21214

Transform

• Three fixes to SAM type handling #​21596
• Fix treatment of separately compiled @native methods in FirstTransform #​21593
• Fix #​20856: Serialize Waiting and Evaluating as if null. #​21243
• Fixes IllegalAccessError with Java package protected class #​21362
• Consistently use TypeMismatch in TreeChecker #​21529
• Fix: don't use color codes for pattern match code action #​21120
• Let show behave more robustly for Recheck #​21678
• Always rewrite empty List() to Nil #​21689

Typer

• Fix extending protected nested java classes #​21857
• Avoid cyclic errors forcing default arg types #​21597
• Survive inaccessible types when computing implicit scope #​21589
• Revert "Drop redundant butNot = Param clause in isAnchor" #​21566
• Fail early & more clearly on shaded-broken classfiles #​21262
• Fix isomorphism tests of AndOrTypes under non-empty BinderPairs #​21017
• Some fixes for AnnotatedTypes mapping #​19957
• Simple performance improvement for Denotations #​21584
• Avoid import suggestion thread hang if -Ximport-suggestion-timeout <= 1 #​21434
• Fix incorrect caching with dependent method parameters #​21699

Experimental: Explicit Nulls

• Add tracking of NotNullInfo for Match, Case, Try trees (fix #​21380) #​21389
• Fix #​21392: Adjust canComparePredefined(Nothing, T) in explicit nulls #​21504

Contributors

Thank you to all the contributors who made this release possible 🎉

According to git shortlog -sn --no-merges 3.3.4..3.3.5-RC1 these are:

    56  Wojciech Mazur
    14  Dale Wijnand
    10  Katarzyna Marek
     8  rochala
     5  Hamza Remmal
     5  noti0na1
     4  Matt Bovel
     4  Seth Tisue
     4  Som Snytt
     3  Jamie Thompson
     3  Martin Odersky
     3  Michał Pałka
     3  dependabot[bot]
     3  kasiaMarek
     2  Aleksander Rainko
     2  Eugene Flesselle
     2  Florian3k
     2  HarrisL2
     2  Jędrzej Rochala
     2  Kacper Korban
     2  Yichen Xu
     1  Eugene Yokota
     1  Guillaume Martres
     1  Hamza REMMAL
     1  Jan Chyb
     1  Joel Wilsson
     1  Kenji Yoshida
     1  Martin Duhem
     1  Nicolas Stucki
     1  Ondrej Lhotak
     1  Sébastien Doeraene
     1  Tomasz Godzik

v3.3.4

Compare Source

Highlights of the release

• Error when reading class file with unknown newer jdk version #​18618
• Add support for xsbti.compile.CompileProgress #​18739
• Add support for @deprecatedInheritance #​19082
• Bump JLine 3.19.0 -> 3.24.1 & sbt 1.9.7 -> 1.9.9 #​19744
• Repl - method signatures in autocomplete #​19917
• Upgrade Scala 2 to 2.13.14 (was 2.13.12) #​20902

Notable changes

• Backport of #​20463 corrects generic signatures emitted in the JVM bytecode for value classes and aligns it with Scala 2.13 semantics. The previously generated signatures for value classes were invalid - they contained underlying value class type instead of boxed type. This change would lead to MiMa errors when signature checks are enabled and could lead to issues when trying to refer to value class methods using reflection API. It would not affect the normal usage of value classes in Scala code compiled with the previous version of the compiler.

Other changes and fixes

Annotations

• Attempt implicit search for old style implicit parameters in Application matchArgs #​19737

Artifacts

• Add versionLine marker to pom.xml #​19986
• Avoid duplications of properties in pom.xml #​20020

Backend

• Parallelise JVM backend - Scala 2 port #​15392
• Fix Closure span assignment in makeClosure #​15841
• Count size of parameters for platform limit check #​18464
• Opt: Get rid of the LiftTry phase; instead handle things in the back-end. #​18619
• Update asm to 9.6 #​18712
• Don't emit line number for synthetic unit value #​18717
• Avoid too eager transform of $outer for lhs & accessor rhs #​18949
• Make more anonymous functions static #​19251
• Fix deadlock in initialization of CoreBTypes using Lazy container #​19298
• Fix(#​17255): cannot find Scala companion module from Java #​19773
• Change isStatic to isStaticOwner in hasLocalInstantiation #​19803
• Emit switch bytecode when matching unions of a switchable type #​20411
• Fix EnclosingMethod for lifted anonfun #​20558
• Fix deterministically adding additional interfaces #​20593

Coverage

• Correctly prettify names in coverage info #​18542
• Port coverage filter options for packages and files #​19727

Default parameters

• Lift all non trivial prefixes for default parameters #​19739
• Fix default args lookup for given classes #​20256
• Fix implicit search failure reporting #​20261

Derivation

• Fix infinite loop in Mirror synthesis of unreducible match type #​20133

Desugaring

• Make apply proxies work with overloaded ctors #​19464
• Fix possible crash in Desugar #​19567
• Add explanation to checkCaseClassInheritanceInvariant error msg #​20141

Documentation

• [spec] remove implementation details from enum spec #​18579
• [spec] some fixes to tuples #​18582
• [spec] Cosmetic changes in the lexical syntax chapter #​18608
• Spec: Update the list of tokens that can start/end statements. #​18611
• Update syntax.md #​18648
• Sync main with language-reference-stable #​18718
• Completion assert diffs will now show completion source #​18890
• Fix Export Doc #​18952
• reference doc: fix incorrect syntax production #​19017
• State all known limitations of right-associative extension methods #​19210
• Update explicit-nulls.md #​19327
• update old issues.scala-lang.org url #​19606
• Update syntax.md #​19670
• Clear the not-backported documentation changes queue #​19699
• remove implementation from asInstanceOf #​19753
• Port tailrec spec and adjustments to annotations section #​19978
• Optimize the documentation JS files #​20075
• Optimize main.js #​20093
• Improve documentation of implicit conversions #​20103
• Update Quotes.scala #​20174
• Supplement structural givens doc #​20327
• Fix three dead links in spec Types doc chapter #​20337
• Avoid jpath in example #​20775

Erasure

• Make eraseInfo work for classes with EmptyScopes #​19550
• Don't re-balance AndTypes arising from supertypes #​20400

Exports

• Do not propagate @tailrec to exported methods #​19509
• Fix retained flags in exports #​19636
• Add annotations in parameters for exports #​20140
• Fix isAliasType #​20195

GADTs

• Only cache base types when gadt state is empty #​19562

Implicits

• Tweak convertible implicits fix #​18727
• Run CheckStatic after UncacheGivenAliases #​19318
• Add tests to verify that crash is fixed elsewhere. Fixes #​19328 #​19329
• Don't search for implicit conversions to NoType #​19563
• Prefer extensions over conversions for member selection #​19717
• Adjust owner in Interactive.contextOfPath causing crash in ImplicitSearch #​19875
• Improve ConstraintHandling of SkolemTypes #​20175
• Better error diagnostics under -explain-cyclic #​20251
• Bring back ambiguity filter when we report an implicit not found error #​20368
• Avoid stacked thisCall contexts #​20488

Incremental Compilation

• Fix undercompilation upon ctor change #​19911
• Retain default parameters with export #​20167

Inferencing

• Adapt toInstantiate in interpolateTypeVars to consider #​20399 #​20426

Infrastructure

• Fix listing release versions for bisect script. #​19356
• Make tests resilient to exceptions thrown while reporting exceptions #​19566
• Move CI management from lampepfl/dotty-ci #​19697
• Switch to Java 17 in the CI #​19703
• [regression] Publish nightly releases and releases using Java 8 #​19722
• Bump scalacenter/sbt-dependency-submission from 2 to 3 #​20440

Inline

• Fix regression: inline match crash when rhs uses private inlined methods #​18595
• Add structural classes of dynamicApply before inlining #​18766
• Inline transparent implicit parameters when typing Unapply trees #​19646
• Specialized retained inline FunctionN apply methods #​19801
• Restore pre-3.3.2 behavior of inline implicit def #​19877
• Avoid crash after StopMacroExpansion #​19883
• Check deprecation of inline methods #​19914
• Fix by-name parameter in beta-reduction #​20096
• Type desugared transparent inline def unapply call in the correct mode #​20108
• Add warning for anonymous inline classes (#​16723) #​20291
• Avoid conversion of Unit type into () term #​20295
• Fix outerSelect in Inliner #​20313
• Mark genSJSIR as disabled (rather than non-runnable) when no -scalajs. #​20815
• Map over refs of ImportTypes in TypeMap #​20837

Linting

• Implement -Xlint:private-shadow, type-parameter-shadow #​17622
• Fix false positive in WUnused for renamed path-dependent imports #​18468
• Fix false positive in WUnused for renamed path-dependent imports (2) #​18617
• Fix wunused false positive on CanEqual #​18641
• Fix #​20146: attach the original name if there is an import selection for an indent #​20163
• Use final result type to check selector bound #​20989

Match Types

• Cover patterns using reflect.TypeTest in isMatchTypeShaped #​19923
• Do match type reduction atPhaseNoLater than ElimOpaque #​20017
• Use MirrorSource.reduce result for companionPath #​20207

Nullability

• Fix #​19808: Don't force to compute the owner of a symbol when there is no denotation #​19813

Opaque Types

• Fix problems with cycle checks #​19453
• Heal member-select on opaque reference #​19730

Parser

• Tweak java getlitch not to skip zero #​18491
• Fix(#​18265): crash on extension method without type nor RHS #​18743
• Simplify parameter handling in Parser #​18993
• Add support for JEP-409 (sealed classes) + Add javacOpt directive #​19080
• Parser simple expression error recovery change from null to ??? #​19103
• Warn when @​volatile is used on vals #​19462
• Fix(#​16458): regression in xml syntax parsing #​19522
• Fix(#​16459) xml parse regression #​19531
• Fix parsing of conditional expressions in parentheses #​19985

Pattern Matching

• Propagate constant in result of inline match #​18455
• Fix exhaustivity due to separate TypeVar lambdas #​18616
• Consider extension methods in Space isSameUnapply #​18642
• Fix unreachable warning in deeply nested sealed hierarchy #​18706
• Disable match anaylsis in inlined trees #​19190
• Warn about unchecked type tests in primitive catch cases #​19206
• Remove unnecessary and recursive Space decomposition #​19216
• Fix false unreachable due to opaqueness #​19368
• Improve recursive decompose prefix fix #​19375
• Allow constraining a parameter to Nothing #​19397
• Add a test case, proving i15661 is fixed #​19432
• Fix #​20372: Check pattern match exhaustivity in inlined code #​20403

Polyfunctions

• Check user defined PolyFunction refinements #​18457
• Discard poly-functions when trying to resolve overloading #​20181

Presentation Compiler

• Support completions for extension definition parameter #​18331
• Fix: Don't collect map, flatMap, withFilter in for-comprehension #​18430
• Bugfix: Catch exception from the compiler for broken shadowed pickles #​18502
• Bugfix: highlight for enum type params #​18528
• Bugfix: No signature help for local methods #​18594
• Bugfix: add moduleClass imported symbols in IndexedContext #​18620
• Bugfix: Named args completions with default values #​18633
• Fix: match completions for type aliases #​18667
• Bugfix: add multiline comment completion #​18703
• Bugfix: Backticked named arguments #​18704
• Bugfix: [metals] Case completions for tuple type #​18751
• Add missing -Yexplicit-nulls for presentation compiler #​18776
• Completions should prepend, not replace as it is for Scala 2 #​18803
• Bugfix: rename end marker #​18838
• Remove redundant path calculation from Completions in PC #​18889
• Instantiate Type Vars in completion labels of extension methods #​18914
• Presentation compiler: Bugfix for semantic tokens and synthetic decorations #​18955
• Show documentation for value forwarders in completions #​19200
• Bugfix: Document highlight on class constructors #​19209
• Improve signature help by more stable position calculation + better named arg support #​19214
• Bugfix: Completions for extension methods with name conflict #​19225
• Improvement: Support completions for implicit classes #​19314
• Chore: Backport changes from Metals #​19410
• Chore: backport changes from metals #​19452
• Make order of renames and missing imports deterministic #​19468
• Make PC more resilient to crashes #​19488
• Fix goto-def on exported forwarders #​19494
• Use comma counting for all signature help types #​19520
• Chore: Backport changes from Metals #​19592
• Backport pc changes from metals #​19617
• PC: Replace CC with underlying type in completions #​19638
• improvement: Replace synthetic decorations with inlay hints #​19754
• Allow range selection on function parameter to select a parameter list #​19777
• Weekly backport from metals #​19787
• add info implementation to pc #​19812
• Add custom matchers for completions (fuzzy search for presentation compiler) #​19850
• Weekly metals backport #​19921
• Stabilise returned completions by improving deduplication + extra completions for constructors #​19976
• Fix active param index for empty param lists #​20142
• Delias type members in hover #​20173
• Interactive: handle context bounds in extension construct workaround #​20201
• Fix: prefer non-export definition locations #​20252
• Add pattern completion for unapply contexts #​20274
• Don't show enum completions in new keyword context #​20304
• Chore: Backport changes for presentation compiler #​20345
• Chore: Bump mtags to latest stable #​20442
• Weekly metals backport #​20542
• Port pc find references from metals #​20544
• Bugfix: Exclude newer LSP4j, which is built on JDK 11 #​20771

Quotes

• Add missing span to synthesized product mirror #​18354
• Improve non-static macro implementation error message #​18405
• Fix scala 2 macros in traits with type parameters #​18663
• Fallback erasing term references #​18731
• Patch underlyingArgument to avoid mapping into modules #​18923
• Avoid crashes on missing positions #​19250
• Only evaluate transparent inline unapply once #​19380
• Update staging.Compiler.make documentation #​19428
• Error instead of StaleSymbol crash for certain cyclic macro dependencies #​19549
• Refine handling of StaleSymbol type errors #​19605
• Fix module symbol recovery from NoClassDefFoundError #​19645
• Fix HOAS pattern example and error message #​19655
• Add regression test and imporve -Xprint-suspension message #​19688
• Disallow ill-staged references to local classes #​19869
• Add regression test for #​19909 #​19915
• Avoid spurious val binding in quote pattern #​19948
• Fix TermRef prefixes not having their type healed #​20102
• Improve reporting in staging about the possible use of an incorrect class loader #​20137
• Add regression test for issue 20309 #​20387

REPL

• Repl truncation copes with null #​17336
• Catch stackoverflow errors in the highlighter #​19836
• Fix validity period of derived SingleDenotations #​19983
• Fix #​18383: Never consider top-level imports as unused in the repl. #​20310
• Only consider methods with 0 parameters in valueOf #​20543

Reflection

• Allow to beta reduce curried function applications in quotes reflect #​18121
• Make check flags for newMethod, newVal and newBind in Quotes API less restrictive #​18217
• Normalise mirrorType for mirror Synthesis #​19199
• Fix TypeTreeTypeTest to not match TypeBoundsTrees #​19485
• Improve message when tree cannot be shown as source #​19906
• Fix #​19732: quotes.reflect.Ref incorrectly casting This to RefTree #​19930
• Set the inlining phase in the Context used for checking macro trees #​20087
• Fix erasure crash for Inlined rhs of a context function closure #​20398
• Fix #​20458: do not expose ClassInfo in quotes reflect widenTermRefByName #​20468

Reporting

• Warn if extension receiver already has member #​17543
• Deprecation of case class elements #​17911
• Check if a fatal warning issued in typer is silenced, before converting it into an error #​18089
• Improve error message for inaccessible types #​18406
• Elide companion defs to a object extending AnyVal #​18451
• Add regression test for issue i18493 #​18497
• Add better explanation to error message #​18665
• Better error message when accessing private members #​18690
• Improve assertion error message for Apply and TypeApply #​18700
• Fix import suggestion error logging #​18707
• Improve message for discarded pure non-Unit values #​18723
• Better error message when a pattern match extractor is not found. #​18725
• Shorten traces for TypeMismatch errors under -explain #​18742
• Give "did you mean ...?" hints also for simple identifiers #​18747
• Explicitly state empty package in extendedLocationText #​18748
• Better error for definition followed by keyword #​18752
• Better explain message for 'pattern expected' #​18753
• Add hint for nested quotes missing staged Quotes #​18755
• Support src filter in -WConf (Closes #​17635) #​18783
• Better error messages for missing commas and more #​18785
• Avoid diagnostic message forcing crashing the compiler #​19113
• Make sure that the stacktrace is shown with -Ydebug-unpickling #​19115
• Improve failure message of enum fromOrdinal/valueOf #​19182
• Improve asExprOf cast error formatting #​19195
• Fix type mismatch error confusion between types with same simple name #​19204
• Properly identify empty bounds in error message #​19310
• Don't explain erroneous bounds #​19338
• Better error diagnostics for cyclic references #​19408
• Unify completion pos usage, fix presentation compiler crash in interpolation [#​19614](https://redirect.github.com/scala/scala3/pull/1