Issues

• Constructors with 128+ fields use mimalloc's small-object path (assertion in debug, out-of-bounds at -O2)

  koka-lang/koka#938 · Filter by author TimWhiting opened on Sep 27, 2026

• [BUG] (strong-random / pseudo-random) inside a handler operation crashes the Koka 3.2.3 runtime.

  koka-lang/koka#931 · Filter by author algosul opened on Sep 11, 2026
  1

• Internal error: Type.TypeVar.subNew.KindMismatch on a recursive function with E type parameter before H

  koka-lang/koka#930 · Filter by author evermake opened on Aug 24, 2026

• [LSP] Stale diagnostics persist after errors are fixed

  koka-lang/koka#929 · Filter by author kands-code opened on Aug 24, 2026

• Effect type error for tmap-fip.

  koka-lang/koka#926 · Filter by author cgyurgyik opened on Aug 14, 2026

• JS backend miscompiles tail-recursive match in balance-red, producing undefined values

  koka-lang/koka#925 · Filter by author danielbom opened on Aug 13, 2026
  1

• Weird interactions between implicits and named arguments

  koka-lang/koka#912 · Filter by author omegametabroccolo opened on Jul 20, 2026

• Memory leak in string join

  fixed-on-dev
  koka-lang/koka#903 · Filter by author cognivore opened on Jun 26, 2026

• Some amount of scalar arguments cause compiler hang

  koka-lang/koka#891 · Filter by author cognivore opened on May 5, 2026
  2

• use of undeclared identifier

  koka-lang/koka#889 · Filter by author xingjianll opened on May 2, 2026

• Recursive default argument causes effect inference failure (effects do not match)

  koka-lang/koka#888 · Filter by author amistozy opened on May 1, 2026

• Allow specifying generic types at callsite?

  koka-lang/koka#887 · Filter by author timbertson opened on Apr 15, 2026

• Functions with only implicit arguments are never eta-expanded

  koka-lang/koka#879 · Filter by author HeikoRibberink opened on Mar 25, 2026
  1

• Capture-avoiding substitution for forall types

  koka-lang/koka#872 · Filter by author TimWhiting opened on Mar 21, 2026

• NbE workload

  koka-lang/koka#869 · Filter by author SchrodingerZhu opened on Mar 4, 2026

• Rename error<a> to result<a>

  koka-lang/koka#867 · Filter by author HeikoRibberink opened on Feb 11, 2026
  1

• Recursion on two inductive values is spuriously found divergent sometimes

  koka-lang/koka#862 · Filter by author zephyrtronium opened on Jan 21, 2026

• Naming clash not reported between effect function and regular function

  koka-lang/koka#861 · Filter by author timbertson opened on Jan 20, 2026

• Match completeness misses simple cases

  bug
  koka-lang/koka#858 · Filter by author TimWhiting opened on Jan 7, 2026
  3

• Effect widening doesn't occur for effect parameters

  koka-lang/koka#857 · Filter by author timbertson opened on Dec 29, 2025
  1

• Type aliases should not be expanded when containing phantom type parameters.

  bug
  koka-lang/koka#850 · Filter by author TimWhiting opened on Dec 11, 2025

• Broken some inference

  koka-lang/koka#847 · Filter by author TimWhiting opened on Dec 5, 2025
  1

• Can't reference a private type alias in another module

  koka-lang/koka#846 · Filter by author omegametabroccolo opened on Dec 5, 2025

• Publish VS Code extension to Open VSX

  koka-lang/koka#844 · Filter by author wackbyte opened on Nov 30, 2025

• FFI documentation

  koka-lang/koka#843 · Filter by author jhidding opened on Nov 30, 2025