Name the symbol that we couldn't find

Wilfred · Wilfred · commit 5435640f4ec4 · 2016-12-08T15:51:12.000Z
If the user doesn't have point on the correct variable, this helps them
realise what's wrong.
diff --git a/pyimport.el b/pyimport.el
@@ -141,7 +141,7 @@ Dumb: just scans open Python buffers."
                (line (pyimport--import-simplify example-line symbol)))
           (pyimport--insert-import line)
           (message "%s (from %s)" line (get-text-property 0 'pyimport-path example-line)))
-      (user-error "No matches found"))))
+      (user-error "No matches found for %s" symbol))))
 
 (defun pyimport--extract-unused-var (flycheck-message)
   "Extract the import variable name from FLYCHECK-MESSAGE.
