Issues

• ICE trying to downcast to virtual type in nested yields

  ICEkind:bugtopic:compiler:semantic
  Bug

  crystal-lang/crystal#17543 · Filter by author 396bit opened on Oct 4, 2026
  1

• EPERM raises a plain File::Error, so find_executable aborts on a sandbox-denied PATH entry

  kind:bugtopic:stdlib:system
  Bug

  crystal-lang/crystal#17540 · Filter by author jochenseeber opened on Oct 4, 2026
  3

• Crystal::Once keeps a failed initializer registered (false recursion, compiler crash)

  kind:bugtopic:stdlib:runtime
  Bug

  crystal-lang/crystal#17539 · Filter by author jochenseeber opened on Oct 4, 2026

• A wrong argument to a receiverless call in a with ... yield block reports undefined constant

  kind:bugtopic:compiler:semantic
  crystal-lang/crystal#17523 · Filter by author jochenseeber opened on Oct 2, 2026

• A subclass of a generic instance stops matching it once the type argument gains a later subclass

  topic:compiler:semantic
  Bug

  crystal-lang/crystal#17522 · Filter by author jochenseeber opened on Oct 2, 2026

• Regex::PCRE2#jit_compile raises ArgumentError on memory/security restrictions instead of falling back to interpreter

  kind:bugtopic:stdlib:text
  Bug

  crystal-lang/crystal#17519 · Filter by author renich opened on Oct 1, 2026

• Overwriting a union ivar with a narrower variant leaves stale references in its unused bytes, leaking memory under Boehm GC

  kind:bug
  Bug

  crystal-lang/crystal#17509 · Filter by author bararchy opened on Sep 29, 2026
  6

  

• Codegen BUG: trying to downcast Gen(String)+ <- Gen(String) with a generic subclass and a recursive tuple-returning method

  crystal-lang/crystal#17507 · Filter by author papilip opened on Sep 29, 2026
  2

• Compiler crash: Cast from Nil to Crystal::ProcInstanceType failed (bindings.cr:596) — a NoReturn-typed argument to an overloaded method, inside a typed, closured block

  kind:bug
  Bug

  crystal-lang/crystal#17504 · Filter by author ralsina opened on Sep 29, 2026

• Let a macro read the annotations on its call

  kind:featuretopic:lang:macros
  Feature

  crystal-lang/crystal#17498 · Filter by author jochenseeber opened on Sep 28, 2026
  6

• crystal tool expand finds no expansion inside a method called from a variable initializer

  crystal-lang/crystal#17495 · Filter by author jochenseeber opened on Sep 28, 2026

• TypeNode#name(generic_args: false) includes generic arguments of tuples, procs and metaclasses

  crystal-lang/crystal#17492 · Filter by author jochenseeber opened on Sep 28, 2026

• Show macro run count and runtime after compile --stats ("Macro runs:" is misleading)

  kind:feature
  Feature

  crystal-lang/crystal#17490 · Filter by author compumike opened on Sep 27, 2026

• TypeNode#type_vars on a named tuple returns the named tuple itself

  crystal-lang/crystal#17487 · Filter by author jochenseeber opened on Sep 27, 2026
  7

• Spec::Expectations#be documentation incomplete

  kind:docstopic:stdlib:specs
  Bug

  crystal-lang/crystal#17483 · Filter by author swsch opened on Sep 26, 2026

• A crystal process can delete the cache directory of another running build

  kind:bugtopic:compiler:cli
  Bug

  crystal-lang/crystal#17481 · Filter by author jochenseeber opened on Sep 26, 2026
  8

• crystal tool expand shows finished hook expansions rewritten by cleanup

  crystal-lang/crystal#17474 · Filter by author jochenseeber opened on Sep 25, 2026

• Doc comment on a private/protected member of an enum is dropped by the parser

  kind:bugtopic:compiler:parser
  Bug

  crystal-lang/crystal#17470 · Filter by author jochenseeber opened on Sep 25, 2026

• to_s(emit_doc: true) emits the doc inside private/protected, producing unparsable output

  kind:bugtopic:compiler:parser
  Bug

  crystal-lang/crystal#17468 · Filter by author jochenseeber opened on Sep 25, 2026
  4

• Shared library linking fails with multi-module codegen because @ in Crystal symbols is interpreted as ELF symbol versioning

  kind:bugtopic:compiler:codegen
  crystal-lang/crystal#17462 · Filter by author kojix2 opened on Sep 24, 2026 · 1.23.0
  7

• [] of U (Crystal::ArrayLiteral) should have been expanded

  kind:bugtopic:compiler:semantic
  Bug

  crystal-lang/crystal#17446 · Filter by author phil294 opened on Sep 20, 2026

• macro inherited hook for Enum

  kind:featuretopic:lang:macros
  Feature

  crystal-lang/crystal#17430 · Filter by author HertzDevil opened on Sep 16, 2026
  1

• Out-of-range port is reported as a hostname lookup failure

  kind:bugtopic:stdlib:networking
  Bug

  crystal-lang/crystal#17412 · Filter by author hahwul opened on Sep 14, 2026
  1

• with ... yield does not dispatch when the scope is a union

  kind:bugtopic:compiler:semantic
  Bug

  crystal-lang/crystal#17408 · Filter by author jochenseeber opened on Sep 14, 2026

• Wrong location on a macro-generated call after a failed parser lookahead

  kind:bugtopic:compiler:semantictopic:lang:macros
  Bug

  crystal-lang/crystal#17399 · Filter by author jochenseeber opened on Sep 11, 2026