Highlights of the release

• Add the -Wall option that enables all warnings (Plan B) #20577
• Add origin filter to WConf, DeprecationWarning #21404

Other changes and fixes

Implicits

• Streamline tryNormalize with underlyingMatchType #20268

Inference

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

JVM Backend

• Update asm to patched 9.7 #20144

Overloading

• Report only non-overridden unimplemented members #21337

Parser

• SimplePattern errors should now be recovered as wildcard instead of unimplemented expr #21438

Positions

• Fix trailing comma Ident's span #20445

Presentation Compiler

• Implement completions for named tuple fields #21202
• Don't add suffix if brackets already present #21259
• Change mock symbol search #21296
• Fix: completions when parenthesis already provided #21299
• Weekly metals backport #21343
• Backport from metals #21196
• Help implement Metals' infer expected type feature #21390

Reporting

• Fix: don't use color codes for pattern match code action #21120

Runner

• Wrap the arguments passed to the scalac task between " #21322

SemanticDB

• Fix: semanticdb symbol creation when targetName set #20950

TASTy format

• Add child to parent in completion context #21214

Transform

• Fix #20856: Serialize Waiting and Evaluating as if null. #21243

Typeclass Derivation

• Revert "Compensate loss of transitivity" #21356

Typer

• Avoid forcing ctors & parents which caused cycles #17086
• Fix isomorphism tests of AndOrTypes under non-empty BinderPairs #21017
• Fail when a poly function value has a different number of type params than the expected poly function #21248
• Fail early & more clearly on shaded-broken classfiles #21262
• A tweak to type improvement #21312
• Fix #20897: Make Nothing ⋔ Nothing, as per spec. #21241

Experimental Changes

Modularity

• Fix: Only implement a deferred given in a class if its parent won't implement it #21206

Named Tuples

• Re-use isConcrete checking in match types for NamedTuple.From #20947
• Fix: Dealias NamedTuple's name types when resolving NamedTuple's element types #21331

Safe Global Initialization

• Fix exception on sequence matching with drop #21281
• Fix uninitializing fields when evaluating a cached constructor call in global initialization checker #21403

Contributors

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

According to git shortlog -sn --no-merges 3.5.1..3.5.2 these are:

    22  Dale Wijnand
    12  Eugene Flesselle
    11  Katarzyna Marek
    11  Wojciech Mazur
     6  dependabot[bot]
     4  Hamza REMMAL
     4  Kacper Korban
     4  Martin Odersky
     4  Som Snytt
     4  Yichen Xu
     4  kasiaMarek
     3  Jamie Thompson
     2  EnzeXing
     2  Hamza Remmal
     2  Sébastien Doeraene
     1  Jan Chyb
     1  Jędrzej Rochala
     1  Kavin Satheeskumar
     1  Martin Duhem
     1  Matt Bovel
     1  Raphael Jolly
     1  noti0na1
     1  philippus