just print the error, but don't give specific advice

config/boot.rb

@@ -1,6 +1,5 @@
 require 'pathname'
 require 'rubygems'
-require 'scanf'
 
 GEMFILE_EXTENSIONS = [
     '.local',
@@ -26,20 +25,11 @@ end
 begin
   require 'bundler/setup'
 rescue LoadError => e
-  msg = e.to_s
+  $stderr.puts "[*] Bundler failed to load and returned this error:"
-  ver = msg.scanf("You have already activated bundler %d.%d.%d, but your Gemfile requires bundler %d.%d.%d.")
+  $stderr.puts
-  if ver.length == 6
+  $stderr.puts "   '#{e}'"
-    activated_ver = "#{ver[0]}.#{ver[1]}.#{ver[2]}"
+  $stderr.puts
-    wanted_ver = "#{ver[3]}.#{ver[4]}.#{ver[5]}"
+  $stderr.puts "[*] You may need to uninstall or upgrade bundler"
-    $stderr.puts "[*] Bundler #{activated_ver} conflicts with Ruby #{RUBY_VERSION}'s default of #{wanted_ver}."
-    $stderr.puts
-    $stderr.puts "    $ gem uninstall bundler -v #{activated_ver}"
-  else
-    $stderr.puts "[*] Bundler failed to load: '#{e}'"
-    $stderr.puts "[*] Metasploit requires the Bundler gem to be installed. You may need to run:"
-    $stderr.puts
-    $stderr.puts "    $ gem install bundler"
-  end
   exit(1)
 end