Gemfile in chef-vault-4.0.1 vs Gemfile in chef-vault-4.0.6

@@ -20,8 +20,8 @@
 end
 
 group :debug do
   gem "pry"
   gem "pry-byebug"
-  gem "pry-stack_explorer"
+  gem "pry-stack_explorer", "~> 0.4.0" # pin until we drop ruby < 2.6
   gem "rb-readline"
 end