@cadr I think the problem is that parameter lookup should use root-prompt-tag

See the implementation of parameters in chez

@cadr see see https://github.com/racket/racket/blob/a41f58f9d77cfa037c071cd4ec9c1b7750cdd91d/racket/src/cs/rumble/parameter.ss#L42

https://github.com/pycket/pycket/blob/623efcd062a9fa7d1e4a39b2a8e4cbb30fb1fddf/pycket/prims/continuation_marks.py#L89

right the first test there is wrong

I think

https://github.com/racket/racket/blame/a41f58f9d77cfa037c071cd4ec9c1b7750cdd91d/racket/src/cs/rumble/control.ss#L1037

maybe not, it looks like it does the right thing there

we seem to not have this code: https://github.com/racket/racket/blame/a41f58f9d77cfa037c071cd4ec9c1b7750cdd91d/racket/src/cs/rumble/control.ss#L1066-L1067

see this code in C: https://github.com/racket/racket/blob/a41f58f9d77cfa037c071cd4ec9c1b7750cdd91d/racket/src/racket/src/error.c#L4510

the chez code calls chez:raise: https://github.com/racket/racket/blob/a41f58f9d77cfa037c071cd4ec9c1b7750cdd91d/racket/src/cs/rumble/error.ss#L2-L10