Jekyll自定义主题 - gemspec软件包安装错误：意外的一元 - 期待keyword_do

# coding: utf-8

Gem::Specification.new do |spec|
  spec.name          = "myJekyllTheme"
  spec.version       = "1.0.1"
  spec.authors       = ["Mai Walters"]
  spec.email         = ["maiverily@gmail.com"]

  spec.summary       = %q{A simple theme for my CMS class.}
  spec.homepage      = "https://www.github.uconn.edu/mvw13001/myJekyllTheme"
  spec.license       = "MIT"

  spec.files         = `git ls-files -z`.split("\x0").reject { |f| 
f.match(%r{^(test|spec|features)/}) }

  spec.add_runtime_dependency "jekyll", "~> 3.4"
  spec.add_development_dependency "bundler", "~> 1.12"
  spec.add_development_dependency "rake", "~> 10.0"
  spec.add_development_dependency "jekyll-polyglot", ">= 1.2.4"
  spec.add_development_dependency "jekyll-seo-tag", ">= 2.1.0"
  spec.add_development_dependency "jekyll-paginate", ">= 1.1.0"
  spec.add_development_dependency "jekyll-feed", "~> 0.6"
end

我正在使用这个代码尝试创建一个jekyll主题，并且我设置了我的gemspec文件，但是每次运行bundle install时，都会收到此错误消息：

I am using this code to try to create a jekyll theme and I am setting up my gemspec file but every time I run bundle install, I get this error:

C:\Users\M\myJekyllTheme>bundle install

[!] There was an error parsing `Gemfile`: syntax error, unexpected unary-, 
expecting keyword_do or '{' or '(' - ....files         = git ls-files -
z.split("\x0").select { |f| f...
...                               ^. Bundler cannot continue.

 #  from C:/Users/M/myJekyllTheme/Gemfile:15
 #  -------------------------------------------
 #    spec.add_development_dependency "bundler", "~> 1.12"
 >  end #  source "https://rubygems.org"
#  -------------------------------------------

有人知道为什么会这样吗？

Does anyone know why this would be?