Chaining function calls with colon syntax causes 100% Reproducible Crash - Luau Type Checking Beta

[Rocky28447 (Rocky)]

I’ve started experiencing a 100% reproducible crash when I have the new Luau type checking enabled. I’ve narrowed it down to a single function in a single script included with @Crazyman32’s AeroGameFramework. Here is what happens:

• Studio will immediately become and remain unresponsive upon the script being pasted into DataModel
• Studio will continue to exponentially use more and more memory until killed from task manager

I’m including a stripped-down version of the script with the bare minimum needed to reproduce the crash. Simply paste the script into the game with the Luau type checking beta feature enabled to cause the crash.

DateExcerpt.lua (2.0 KB)

Edit: A more precise description of the crash was provided in a reply to this post.

Chaining function calls with colon syntax causes 100% Reproducible Crash - Luau Type Checking Beta

It looks like this is related to chaining function calls. Any chain of function calls will do this, including one using functions that don’t exist. This only happens when using the colon syntax. Doing the following (17 levels deep for me) starts to slow down making script changes, and it seems to get exponentially worse with each additional level. str = str :gsub() :gsub() :gsub() :gsub() :gsub() :gsub() :gsub() :gsub() :gsub() :gsub() :gsub() :gsub() :gsub() :gsub() :gsub() :…

[PeZsmistic]

It looks like this is related to chaining function calls. Any chain of function calls will do this, including one using functions that don’t exist. This only happens when using the colon syntax.

Doing the following (17 levels deep for me) starts to slow down making script changes, and it seems to get exponentially worse with each additional level.

str = str	
	:gsub()
	:gsub()
	:gsub()
	:gsub()
	:gsub()
	:gsub()
	:gsub()
	:gsub()
	:gsub()
	:gsub()
	:gsub()
	:gsub()
	:gsub()
	:gsub()
	:gsub()
	:gsub()
	:gsub()

[Kullaske]

I believe I’m having the same issue happening with RBXSync. (I know that RBXSync is terribly outdated. But old habits never die)

Hopefully this issue will be fixed in the next phase of the beta.

[sleitnick]

Yeah I can confirm this as well. I cannot even load the game in Studio without crashing. Had to turn the feature off.

[Rocky28447 (Rocky)]

This bug has been fixed in the latest release of studio (version 422).

Release Notes for 422

Notes for Release 422

(I’ve verified this in studio.)

[PeZsmistic]

While this no longer lags Studio tremendously, it still crashes with no user-visible reason (exception).