fix rbenv/cache warnings if the directory is empty

Author: bshand

lib/ndr_dev_support/capistrano/install_ruby.rb

@@ -48,8 +48,8 @@
       run <<~SHELL
 echo ----;
 echo Checking what visibility we have:
-echo ls -la #{latest_release}/vendor;
-ls -la #{latest_release}/vendor;
+echo latest_release = \\"#{latest_release}\\"
+ls -la #{latest_release}/vendor/rbenv;
 echo ----;
 
         set -e;
@@ -68,7 +68,7 @@
             if [ ! -e .rbenv ]; then
               echo rbenv not installed: aborting;
             else
-              if [ -d #{latest_release}/vendor/rbenv/cache ]; then
+              if [ -d #{latest_release}/vendor/rbenv/cache ] && [ -n "`ls #{latest_release}/vendor/rbenv/cache`" ]; then
                 mkdir -p .rbenv/cache/;
                 cp -nvp #{latest_release}/vendor/rbenv/cache/* .rbenv/cache/;
               fi;