Do not rely on requiring "find". Cut-and-pasted the code instead.

mongo-ruby-driver.gemspec

@@ -1,4 +1,45 @@
-require 'find'
+# This is a copy of the code in the stdlib file 'find.rb'. GitHub doesn't seem
+# to allow me to "require 'find'".
+module Find
+  def find(*paths) # :yield: path
+    paths.collect!{|d| d.dup}
+    while file = paths.shift
+      catch(:prune) do
+	yield file.dup.taint
+        next unless File.exist? file
+	begin
+	  if File.lstat(file).directory? then
+	    d = Dir.open(file)
+	    begin
+	      for f in d
+		next if f == "." or f == ".."
+		if File::ALT_SEPARATOR and file =~ /^(?:[\/\\]|[A-Za-z]:[\/\\]?)$/ then
+		  f = file + f
+		elsif file == "/" then
+		  f = "/" + f
+		else
+		  f = File.join(file, f)
+		end
+		paths.unshift f.untaint
+	      end
+	    ensure
+	      d.close
+	    end
+	  end
+        rescue Errno::ENOENT, Errno::EACCES
+	end
+      end
+    end
+  end
+
+  def prune
+    throw :prune
+  end
+
+  module_function :find, :prune
+end
+
+# ================================================================
 
 def self.files_in(dir)
   files = []