Release 726 Notes

What a game last night ⚽ 🥳 !

Type System

• Reasonings for subtyping failures with unions are now somewhat abbreviated. In practice this means messages that used to be multiple lines explaining why each element in the union did not relate to the other type are replaced with a single message.

• Fix an error caused by improperly rebinding an erroneous type participating in a cyclic alias. Specifically:

  type A = B type B = { x: C<any> } type C<T> = A no longer triggers an assertion.

• Requirers of a module will now see an error type instead of an erroneous type function, which will reduce the amount of cascading errors displayed.

• Fixes a bug where nilable generic functions would erroneously claim there is a generic bounds mismatch. Fixes [#2393]

Runtime

• General improvements to the Bytecode Graph, including better parsing, serialization, and inlining.

Miscellaneous:

• Reduce stack usage in Luau's parser
• Adds support for attribute lists and parametrized attributes to the CST
• Make the CLI try to find the provided file name with a .luau or .lua extension before erroring by @gaymeowing in https://github.com/luau-lang/luau/pull/2415

Full Changelog: https://github.com/luau-lang/luau/compare/0.725...0.726

Co-authored-by: Andy Friesen afriesen@roblox.com Co-authored-by: Hunter Goldstein hgoldstein@roblox.com Co-authored-by: Ilya Rezvov irezvov@roblox.com Co-authored-by: James McNellis jmcnellis@roblox.com Co-authored-by: Sora Kanosue skanosue@roblox.com Co-authored-by: Thomas Schollenberger tschollenberger@roblox.com Co-authored-by: Vighnesh Vijay vvijay@roblox.com