[wip] when no tempdir: try (clojure-project-dir) as fallback first

Author: vroide

cider-util.el

@@ -530,8 +530,10 @@ Any other value is just returned."
 
 (defun cider--make-nearby-temp-copy (file)
   (with-demoted-errors "Failed to copy to temporary file:\n %s"
-    (let ((new-file (file-name-concat (temporary-file-directory)
-                                      (cider--make-temp-name file))))
+    (let* ((default-directory (or (clojure-project-dir) default-directory))
+           ;; Note: (temporary-file-directory) uses `default-directory' as fallback.
+           (new-file (file-name-concat (temporary-file-directory)
+                                       (cider--make-temp-name file))))
       (copy-file file new-file :exists-ok nil nil :keep-permissions)
       new-file)))