Brent Westbrook <bwestbr2@go.olemiss.edu> writes:

> Attempting to install the projectile package from melpa leads to the
> following (abbreviated) Backtrace:
>
> Debugger entered--Lisp error: (wrong-type-argument symbolp 63)

This appears to be related to commit that João made last November:

--8<---------------cut here---------------start------------->8---
commit 817140a852e79c5ef3cf7dc5e4c50aa710e8c4a2
Author: João Távora <joaotavora@gmail.com>
Date:   Thu Nov 30 07:32:50 2023 -0600

    Fix prefix discovery for files with read-symbol-shorthands (bug#67325)
    
    In a previous commit, the local-variable read-symbol-shorthands is
    already read into the temporary buffer used for the autoload parsing
    aerobatics, so all we needed to do in 'l-g--compute-prefixes' is
    use 'read' to give 'read-symbol-shorthands' a chance to kick in.
    
    * lisp/emacs-lisp/loaddefs-gen.el
    (loaddefs-generate--compute-prefixes):

diff --git a/lisp/emacs-lisp/loaddefs-gen.el b/lisp/emacs-lisp/loaddefs-gen.el
index bf5cd24f161..8aacbf406b6 100644
--- a/lisp/emacs-lisp/loaddefs-gen.el
+++ b/lisp/emacs-lisp/loaddefs-gen.el
@@ -499,7 +499,11 @@ loaddefs-generate--compute-prefixes
     (while (re-search-forward
             "^(\\(def[^ \t\n]+\\)[ \t\n]+['(]*\\([^' ()\"\n]+\\)[\n \t]" nil t)
       (unless (member (match-string 1) autoload-ignored-definitions)
-        (let ((name (match-string-no-properties 2)))
+        (let* ((name (match-string-no-properties 2))
+               ;; Consider `read-symbol-shorthands'.
+               (probe (let ((obarray (obarray-make)))
+                        (car (read-from-string name)))))
+          (setq name (symbol-name probe))
           (when (save-excursion
                   (goto-char (match-beginning 0))
                   (or (bobp)
--8<---------------cut here---------------end--------------->8---

and the fact that Projectile has this line

--8<---------------cut here---------------start------------->8---
(def-projectile-commander-method ?? "Commander help buffer."
--8<---------------cut here---------------end--------------->8---

where the `name' variable above gets bound to the string "??", that when
passed through `read-from-string' eventually gives us the character ??
(ASCII 63), which one cannot pass to `symbol-name'.  So it might be that