Index: db/migrate/20170320051650_change_repositories_extra_info_limit.rb
===================================================================
--- db/migrate/20170320051650_change_repositories_extra_info_limit.rb	(nonexistent)
+++ db/migrate/20170320051650_change_repositories_extra_info_limit.rb	(working copy)
@@ -0,0 +1,12 @@
+class ChangeRepositoriesExtraInfoLimit < ActiveRecord::Migration
+  def up
+    if ActiveRecord::Base.connection.adapter_name =~ /mysql/i
+      max_size = 16.megabytes
+      change_column :repositories, :extra_info, :text, :limit => max_size
+    end
+  end
+
+  def down
+    # no-op
+  end
+end