Well, I think this is the same as my problem and commented there rather than open a new issue: [https://github.com/nim-lang/Nim/issues/13071](https://github.com/nim-lang/Nim/issues/13071).
cpp vs c target also does not seem to matter. Using `CatchableError`, presumably the root of catchable exceptions also does not matter -- making that issue title perhaps overly specific.
