Make debug-early-backtrace more resilient

* lisp/emacs-lisp/debug-early.el (debug-early-backtrace): Allow
outputting backtraces during bootstrap.

diff --git a/lisp/emacs-lisp/debug-early.el b/lisp/emacs-lisp/debug-early.el
index 4f1f4b81557694569f5786612a30d9dcf91077b7..a301c73017e0c2e00606c81a609a1d095169c50c 100644 (file)
--- a/lisp/emacs-lisp/debug-early.el
+++ b/lisp/emacs-lisp/debug-early.el
@@ -45,7 +45,13 @@ of the build process."
       (let ((print-escape-newlines t)
             (print-escape-control-characters t)
             (print-escape-nonascii t)
-            (prin1 (if (fboundp 'cl-prin1) #'cl-prin1 #'prin1)))
+            (prin1 (if (and (fboundp 'cl-prin1)
+                            ;; If we're being called while
+                            ;; bootstrapping, we won't be able to load
+                            ;; cl-print.
+                            (require 'cl-print nil t))
+                       #'cl-prin1
+                     #'prin1)))
         (mapbacktrace
          #'(lambda (evald func args _flags)
              (let ((args args))