Providing a recursive prefab type causes expansion to diverge

[LiberalArtist]

What version of Racket are you using?

7.5 CS (Still true on 7.9.0.900 CS)

What program did you run?

#lang typed/racket/base

(provide (prefix-out prefixed-
                     (struct-out container)))

(struct container
  ([value : (U #f container)])
  #:prefab)

The #:prefab declaration, the type-level recursion, and prefix-out [ETA: or prefix-in, rename-out, or rename-in—see below] all seem to be necessary ingredients.

See below for an example without renaming.

What should have happened?

Macro expansion should terminate.

If you got an error message, please include it here.

In DrRacket: "Background expansion terminated abnormally (out of memory)" and "Interactions disabled; out of memory"

At the command line:

^Cuser break
  context...:
   p
   check-break-prefix
   bitwise-arithmetic-shift-left
   loop
   equal-hash-loop
   key-equal-hash-code
   $gen-hashtable-ref
   hash-ref/none
   hash-ref
   /Applications/Racket v7.5/share/pkgs/typed-racket-lib/typed-racket/types/resolve.rkt:171:0: resolve-once
   /Applications/Racket v7.5/collects/racket/match/compiler.rkt:507:40: f683
   /Applications/Racket v7.5/share/pkgs/typed-racket-lib/typed-racket/types/subtype.rkt:62:0: subtype14
   /Applications/Racket v7.5/collects/racket/list.rkt:600:2: loop
   /Applications/Racket v7.5/share/pkgs/typed-racket-lib/typed-racket/types/union.rkt:27:0: merge
   /Applications/Racket v7.5/collects/racket/private/list.rkt:232:7: loop
   /Applications/Racket v7.5/share/pkgs/typed-racket-lib/typed-racket/types/union.rkt:40:0: normalize-type

[LiberalArtist]

This variant with prefix-in seems to have the same problem (also with #lang racket/base):

#lang typed/racket/base

(module server typed/racket/base
  (provide (struct-out container))
  (struct container
    ([value : (U #f container)])
    #:prefab))
(require (prefix-in prefixed-
                    (submod "." server)))

[LiberalArtist]

These variants with rename-in and rename-out are likewise broken:

#lang typed/racket/base

(module server typed/racket/base
  (provide container)
  (struct container
    ([value : (U #f container)])
    #:prefab))

(require (rename-in (submod "." server)
                    [container prefixed-container]))

#lang typed/racket/base

(provide (rename-out [container container*]))

(struct container
  ([value : (U #f container)])
  #:prefab)

[LiberalArtist]

In fact, renaming doesn't seem to be needed at all, just exporting a recursive prefab type. For example, on Racket 7.9.0.900 [cs], trying to expand this program runs out of memory:

#lang typed/racket/base

(provide container)

(struct container
  ([value : (U #f container)])
  #:prefab)