Datamapper DataMapper

The following specs fail on my system for extlib.

ruby -v
ruby 1.8.7 (2008-05-31 patchlevel 0) [i486-linux]

1)
ArgumentError in 'LazyArray should return self'
wrong number of arguments (2 for 1)
/usr/src/dm/extlib/lib/extlib/lazy_array.rb:20:in `respond_to?'
/usr/src/dm/extlib/lib/extlib/lazy_array.rb:20:in `concat'
/usr/src/dm/extlib/lib/extlib/lazy_array.rb:20:in `concat'
./spec/lazy_array_spec.rb:86:

2)
ArgumentError in 'LazyArray should concatenate another lazy array with #concat'
wrong number of arguments (2 for 1)
/usr/src/dm/extlib/lib/extlib/lazy_array.rb:20:in `respond_to?'
/usr/src/dm/extlib/lib/extlib/lazy_array.rb:20:in `concat'
/usr/src/dm/extlib/lib/extlib/lazy_array.rb:20:in `concat'
./spec/lazy_array_spec.rb:90:

3)
ArgumentError in 'LazyArray should return self'
wrong number of arguments (2 for 1)
/usr/src/dm/extlib/lib/extlib/lazy_array.rb:44:in `respond_to?'
/usr/src/dm/extlib/lib/extlib/lazy_array.rb:44:in `replace'
/usr/src/dm/extlib/lib/extlib/lazy_array.rb:44:in `replace'
./spec/lazy_array_spec.rb:414:

4)
ArgumentError in 'LazyArray should replace itself with the other object'
wrong number of arguments (2 for 1)
/usr/src/dm/extlib/lib/extlib/lazy_array.rb:44:in `respond_to?'
/usr/src/dm/extlib/lib/extlib/lazy_array.rb:44:in `replace'
/usr/src/dm/extlib/lib/extlib/lazy_array.rb:44:in `replace'
./spec/lazy_array_spec.rb:418:

5)
ArgumentError in 'LazyArray should be loaded afterwards'
wrong number of arguments (2 for 1)
/usr/src/dm/extlib/lib/extlib/lazy_array.rb:44:in `respond_to?'
/usr/src/dm/extlib/lib/extlib/lazy_array.rb:44:in `replace'
/usr/src/dm/extlib/lib/extlib/lazy_array.rb:44:in `replace'
./spec/lazy_array_spec.rb:426:

I provided a patch that fixes the problem. A call other.to_a fixes the problem.

The culprit:

  def replace(other)
    mark_loaded
    @array.replace(other)
    self
  end

becomes

  def replace(other)
    mark_loaded
    @array.replace(other.to_a)
    self
  end

I have no idea what happens here. Any ideas?