Slime fails to install on Emacs 29

[sdilts]

Slime doesn't install when using the Emacs package manager on Emacs 29, and fails with the following output (taken from *Messages*):

Install package ‘slime-2.27’? (y or n) y
Contacting host: stable.melpa.org:443
Parsing tar file...done
Extracting...done
  INFO     Scraping files for loaddefs... 
macrostep: Warning: Use keywords rather than deprecated positional arguments to `define-minor-mode'
  INFO     Scraping files for loaddefs...done
  GEN      ../../../../../../home/stuart/.emacs.d/elpa/macrostep-0.9/macrostep-autoloads.el
Checking /home/stuart/.emacs.d/elpa/macrostep-0.9... [2 times]
macrostep.el: Warning: Use keywords rather than deprecated positional arguments to `define-minor-mode'
Wrote /home/stuart/.emacs.d/elpa/macrostep-0.9/macrostep-c.elc
Checking /home/stuart/.emacs.d/elpa/macrostep-0.9... [2 times]
Wrote /home/stuart/.emacs.d/elpa/macrostep-0.9/macrostep.elc
Checking /home/stuart/.emacs.d/elpa/macrostep-0.9...
Done (Total of 2 files compiled, 2 skipped)
Contacting host: stable.melpa.org:443 [2 times]
Parsing tar file...done
Extracting...done
  INFO     Scraping files for loaddefs... 
slime-tests:0: Warning: Not registering prefix "sl".  Affects: ("sldb-level" "sldb-first-abort-restart" "slime-at-top-level-p" "slime-wait-condition" "slime-shuffle-list" "slime-skip-test" "slime-sync-to-top-level" "slime-sldb-level=" "slime-check" "slime-check-top-level" "slime-check-sldb-level" "slime-check-symbol-at-point" "slime-batch-test" "slime-buffer-visible-p" "slime-inspector-visible-p" "slime-execute-as-command" "slime-tests--undefine-all" "slime-test--display-region-eval-arg" "slime-test--display-region-line-to-position" "slime-test--compile-defun" "slime-test-macroexpansion=" "slime-test-expect" "slime-test-eval-now" "slime-recompile-all-xrefs")
  INFO     Scraping files for loaddefs...done
package-generate-autoloads: Search failed: "
"

There's actually an unprintable character in the last line that renders as ^L:

package-generate-autoloads: Search failed: "^L
"

I'm using Emacs commit 1d3fe256907d5e78a4acedd194e55db8ab952952 on Fedora 36. On Emacs 28.1 from the package manager, it installs fine. I wouldn't be surprised if this was an bug in emacs itself, but since other packages seem to install correctly, I thought I'd report it here first.

Steps to reproduce:

First, move your .emacs file and remove ~/.emacs.d, or change the environment variable XDG_CONFIG_HOME Run emacs -q

Next, run the following forms to setup the package repos:

(require 'package)
(add-to-list 'package-archives
        '("melpa-stable" . "https://stable.melpa.org/packages/") t)

Finally, use M-x list-packages to find slime version 2.27 and install it.