Errors in test suite under 1.8.6-p399 related to Mocha?

I get the following errors when running under 1.8.6

  1) Error:
test_exists_without_http_mock(BaseTest):
NoMethodError: undefined method `any_instance' for ActiveResource::Connection:Class
    ./test/base_test.rb:989:in `test_exists_without_http_mock'

  2) Error:
test_accept_http_header(ConnectionTest):
NoMethodError: undefined method `mock' for #<ConnectionTest:0xb794ecd0>
    ./test/connection_test.rb:203:in `test_accept_http_header'

  3) Error:
test_ssl_error(ConnectionTest):
NoMethodError: undefined method `expects' for #<ActiveResource::Connection:0xb7be39a0>
    ./test/connection_test.rb:223:in `test_ssl_error'

  4) Error:
test_timeout(ConnectionTest):
NoMethodError: undefined method `mock' for #<ConnectionTest:0xb794e99c>
    ./test/connection_test.rb:185:in `test_timeout'

161 tests, 500 assertions, 0 failures, 4 errors
rake aborted!
Command failed with status (1): [/home/vagrant/.rvm/rubies/ruby-1.8.6-p399/...]