Fix some file permissions errors

Occurs when deferred packages are loaded while in an unreadable or
non-existent directory.

core/core-modules.el

@@ -298,7 +298,12 @@ This value is cached. If REFRESH-P, then don't use the cached value."
                  (lambda (&rest _)
                    (doom-log "Loading deferred package %s from %s" ',name ',fn)
                    (condition-case e
-                       (require ',name)
+                       ;; If `default-directory' is a directory that doesn't
+                       ;; exist or is unreadable, Emacs throws up file-missing
+                       ;; errors, so we set it to a directory we know exists and
+                       ;; is readable.
+                       (let ((default-directory doom-emacs-dir))
+                         (require ',name))
                      ((debug error)
                       (message "Failed to load deferred package %s: %s" ',name e)))
                    (when-let (deferral-list (assq ',name doom--deferred-packages-alist))

core/core.el

@@ -344,7 +344,13 @@ intervals."
         (when-let (req (if reqs (pop reqs)))
           (doom-log "Incrementally loading %s" req)
           (condition-case e
-              (or (while-no-input (require req nil t) t)
+              (or (while-no-input
+                    ;; If `default-directory' is a directory that doesn't exist
+                    ;; or is unreadable, Emacs throws up file-missing errors, so
+                    ;; we set it to a directory we know exists and is readable.
+                    (let ((default-directory doom-emacs-dir))
+                      (require req nil t))
+                    t)
                   (push req reqs))
             ((error debug)
              (message "Failed to load '%s' package incrementally, because: %s"