Cannot load ASDF

[phantomics]

I'm attempting to load the ASDF library, a very popular tool for defining software systems within other CL implementations. It's failing after I do the following steps in an XCL exec window:

In XCL:

(XCL:DEFINE-FILE-ENVIRONMENT ASDF :PACKAGE (DEFPACKAGE "ASDF" (:USE "LISP" "XCL")) :READTABLE "XCL")
(DEFPACKAGE "ASDF" (:USE "LISP" "XCL"))
(IL:FILESLOAD TEXTMODULES)
(tm:load-textmodule "<home>user>quicklisp>asdf.lisp" :module "ASDF" :package (find-package "ASDF") :install t)

The resulting error message:

In IL:RESOLVE-EXPORT-MISSING
<Condition EXPORT-MISSING @ 136,74770>
(problems trying to report it!)

The stack trace indicates that the problem occurs in this form:

(defpackage :uiop/package
  ;; CAUTION: we must handle the first few packages specially for hot-upgrade.
  ;; This package definition MUST NOT change unless its name too changes;
  ;; if/when it changes, don't forget to add new functions missing from below.
  ;; Until then, uiop/package is frozen to forever
  ;; import and export the same exact symbols as for ASDF 2.27.
  ;; Any other symbol must be import-from'ed and re-export'ed in a different package.
  (:use :common-lisp)
  (:export
   #:find-package* #:find-symbol* #:symbol-call
   #:intern* #:export* #:import* #:shadowing-import* #:shadow* #:make-symbol* #:unintern*
   #:symbol-shadowing-p #:home-package-p
   #:symbol-package-name #:standard-common-lisp-symbol-p
   #:reify-package #:unreify-package #:reify-symbol #:unreify-symbol
   #:nuke-symbol-in-package #:nuke-symbol #:rehome-symbol
   #:ensure-package-unused #:delete-package*
   #:package-names #:packages-from-names #:fresh-package-name #:rename-package-away
   #:package-definition-form #:parse-define-package-form
   #:ensure-package #:define-package))

What could the cause be?

[hjellinek]

The problem appears to relate to problems dealing with uninterned symbols in the current Medley implementation.

Per @masinter, the simplest fix is to complete the integration of CLtL2.