This patch removes the usage of git in gemspec.
---

--- ruby-expression-parser.orig/expression_parser.gemspec
+++ ruby-expression-parser/expression_parser.gemspec
@@ -12,8 +12,8 @@ spec = Gem::Specification.new do |s|
   s.homepage = "http://github.com/nricciar/expression_parser"
   s.platform = Gem::Platform::RUBY
   s.summary = "Math parser based on Lukasz Wrobel's blog post"
-  s.files = `git ls-files`.split("\n")
-  s.test_files = `git ls-files -- {test,spec,features}/*`.split("\n")
+  s.files = ''
+  s.test_files = ''
   s.require_path = "lib"
   s.description = File.read("README")
   s.has_rdoc = false