Here's a simple way to roll your own enums:

(define-syntax define-enum
   (syntax-rules ()
     ((define-enum enum symbol ...)
      (begin (define symbol 'symbol) ...
             (define enum '(symbol ...))))))

(define-enum errno
   EPERM
   ENOENT
   ESRCH
   EINTR
   EIO
   ENXIO
   E2BIG
   ENOEXEC
   EBADF
   ECHILD
   EDEADLK
   ENOMEM
   EACCES
   EFAULT)

Now typos such as (codeset-message 'errno ECHILE) will be caught.

A safer version such as (codeset-message errno (errno ECHILE)) can
probably be done with syntax-case.

As discussed in an earlier email on this list, it's not appropriate to
define standard enums since the full set of values seen in the wild
cannot be standardized. Each application or library wishing to use safe
enums should list the codes that it needs.