Re: obscure compilation error with cl-defstruct &aux boa constructor

[Stefan Monnier]

Madhu [2022-04-16 22:16:18] wrote:
>       byte-code("#!E\"" [set-advertised-calling-convention cl-prettyexpand 
> (form) "27.1" require help-mode add-to-list describe-symbol-backends nil 
> cl-find-class #[771 "!" [cl-describe-type] 5 "\n\n(fn S B F)"]] 5)
>       cl-subseq((&cl-defs (nil (cl-tag-slot) (stack) (ppss) (ppss-point)) 
> &optional (ppss (lisp-ppss)) &aux (ppss-point (point)) (stack (make-list (1+ 
> (car ppss)) nil))) 0 4)

It looks like some frames are missing between these two.

> The error goes away if I remove the &aux (and thus make all the
> arguments optional)

I must say that seeing your backtrace I can't understand why your code
doesn't work or rather why our code works (the call to `cl-subseq`
depends on the presence of `&aux` which is already present in our code).

> Might this be a bug from a recent change? (I've not looked at the
> changes yet, so this is a note to self)

The bootstrap is delicate and ad-hoc.
Sometimes innocuous changes can break it.


        Stefan