Fix treemacs-project-toggle

Avoid error in spacemacs startup buffer

CHANGELOG.develop

@@ -2585,6 +2585,8 @@ Other:
   ~C-x w 0~, ~SPC 0~ and ~M-0~ call the same command (thanks to duianto, Miciah)
 - Loaded =treemacs-projectile= key binding ~C-c C-p p~ with Treemacs
   (thanks to duianto)
+- Handle ~SPC p t~ when =projectile-project-root= is nil (thanks to Trapez
+  Breen)
 **** Typescript
 - Call tsfmt with extension of current buffer for TSX formatting
   (thanks to Victor Andrée)

layers/+filetree/treemacs/funcs.el

@@ -14,7 +14,7 @@
   (interactive)
   (if (eq (treemacs-current-visibility) 'visible)
       (delete-window (treemacs-get-local-window))
-    (let ((path (projectile-project-root))
+    (let ((path (projectile-ensure-project (projectile-project-root)))
           (name (projectile-project-name)))
       (unless (treemacs-current-workspace)
         (treemacs--find-workspace))