gem build fleakr.gemspec raises exception

[base10]

Running gem build fleakr.gemspec raises the following exception:

ERROR:  While executing gem ... (Gem::InvalidSpecificationException)
    ["lib/fleakr/core_ext", "lib/fleakr/core_ext/false_class.rb", "lib/fleakr/core_ext/hash.rb", "lib/fleakr/core_ext/true_class.rb", "lib/fleakr/core_ext.rb", "test/unit/fleakr/core_ext", "test/unit/fleakr/core_ext/false_class_test.rb", "test/unit/fleakr/core_ext/hash_test.rb", "test/unit/fleakr/core_ext/true_class_test.rb"] are not files