Thanks for forwarding these to the SRFI 198 list.

> Exposing that e.g. errno 2 is ENOENT has been my pet project for SRFI 170,

For that you need a groveler, and once you have one, putting together an
enumerable errno collection becomes trivial enough that we might as well
do it in a standard way. We'd just read the groveler's dump of errno
values into pretty much any Scheme data structure and add a little API
to walk that data structure.

> and a regularized system to both
> create and query such a catalog would be great.  And naturally used
> to replace the ad hoc hash table map I currently use.
>
> If John and the community at large agrees this is the Right Thing, can
> you provide some code to implement these APIs?

Sure, I can implement them.