Have the bundle command explode with a helpful error message if older versions of bundler exist.

1 files changed, 7 insertions, 0 deletions

diff --git a/bin/bundle b/bin/bundle
index ea455093..6fab3004 100644
--- a/bin/bundle
+++ b/bin/bundle
@@ -1,3 +1,10 @@
+# Check if an older version of bundler is installed
+require 'bundler'
+$:.each do |path|
+  if path =~ %r'/bundler-0.(\d+)' && $1.to_i < 9
+    abort "Please remove older versions of bundler. This can by running `gem cleanup`."
+  end
+end
 require 'bundler/cli'
 
 begin