Stream: bugs

Topic: Panic use-after-free for List.with_capacity

view this post on Zulip Matthieu Pizenberg (Dec 13 2025 at 20:18):

The following panics with a use after free. It doesn’t panic when the accum is initialized with [] instead.

main! = || {
    _x = [""].fold(List.with_capacity(1), List.append)
}

More details in issue https://github.com/roc-lang/roc/issues/8667

Last updated: Dec 21 2025 at 12:15 UTC