[racket] module-path-index and self-paths

I'm trying to trace down a bug in my code down to a user of
module-path-index-resolve.  I'm somehow getting a hold of a
module-path-index with the following structure:

    (module-path-index-join "private/base.rkt"
                                      (module-path-index-join #f #f))


When given this, module-path-index-resolve errors out and says:

    module-path-index-resolve: "self" index has no resolution:
#<module-path-index>


I'm trying to figure out if I'm misusing module-path-index-resolve.  I
am getting this particular module path index by zo-parsing
collects/racket/base.rkt and looking into its phase-0 requires.

Here is code to demonstrate where the value is coming from:

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
#lang racket
(require racket/match
         compiler/zo-parse)

(define (run-zo-parse path)
  (parameterize ([current-namespace (make-base-namespace)]
                 [read-accept-reader #t]
                 [current-directory
                  (let-values ([(base file is-dir)
                                (split-path path)])
                    base)])
    (let ([bc (compile (read (open-input-file path)))]
          [op (open-output-bytes)])
      (write bc op)
      (zo-parse (open-input-bytes (get-output-bytes op))))))


;; Splits up a module path index into its components.
(define (explode-module-path-index mpi)
  (let-values ([(x y) (module-path-index-split mpi)])
    (cond
      [(module-path-index? y)
       (cons x (explode-module-path-index y))]
      [else
       (list x y)])))


(match (run-zo-parse (build-path (find-system-path 'collects-dir)
                                 "racket"
                                 "base.rkt"))
  [(struct compilation-top (_
                            _
                            (struct mod (_ _ _ _ _ requires _ _ _ _ _ _ _))))
   (for ([phase-and-paths requires])
     (when (equal? (car phase-and-paths) 0)
       (displayln (map explode-module-path-index (cdr phase-and-paths)))))])
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;


The second element in the list value that displays:

    ((racket/private/pre-base #f) (private/base.rkt #f #f))

is the module-path-index that I don't quite know how to resolve into a
nice resolved-module-path.