缺少突变体-rspec？

Question

我正在尝试使用来自存储库的 ruby 2.1.5+deb8u2 和 ruby-dev 2.1.5+deb8u2 包在新安装的 Debian 8.5 上设置一个新的 Ruby 项目。我想在我的项目中包括突变测试。我添加了mutant-rspec 到我的Gemfile：

source 'https://rubygems.org'

gem 'rake'
gem 'rspec', require: 'spec'
gem 'mutant-rspec'

Bundler (1.13.0) 似乎可以很好地安装 gem

ytg@debian-vm:~/projects/new_project$ bundle install
Fetching gem metadata from https://rubygems.org/..........
Fetching version metadata from https://rubygems.org/.
Using rake 11.2.2
....
Using rspec-core 3.5.3
Using rspec-expectations 3.5.0
Using rspec-mocks 3.5.0
...
Using rspec 3.5.0
...
Installing mutant 0.8.11
Installing mutant-rspec 0.8.11
Bundle complete! 5 Gemfile dependencies, 34 gems now installed.
Use `bundle show [gemname]` to see where a bundled gem is installed.

现在如果我尝试运行mutant，使用rake mutant --trace 和rake 文件

require 'bundler/gem_tasks'
require 'rspec/core/rake_task'
require 'rubocop/rake_task'
require 'mutant'

RSpec::Core::RakeTask.new :spec

task default: :spec

RuboCop::RakeTask.new

task :mutant do
  result = Mutant::CLI.run %w(--since problem9 -Ilib -Ispec
                              --use rspec MyProject*)
  raise 'Mutation testing failed' unless result
end

我收到一条错误消息：

warning: parser/current is loading parser/ruby21, which recognizes
warning: 2.1.8-compliant syntax, but you are running 2.1.5.
warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.
** Invoke mutant (first_time)
** Execute mutant
Could not load integration "rspec" (you may want to try installing the gem mutant-rspec)
rake aborted!
Mutation testing failed
/home/ytg/projects/new_project/Rakefile:15:in `block in <top (required)>'
/var/lib/gems/2.1.0/gems/rake-11.2.2/lib/rake/task.rb:248:in `call'
/var/lib/gems/2.1.0/gems/rake-11.2.2/lib/rake/task.rb:248:in `block in execute'
/var/lib/gems/2.1.0/gems/rake-11.2.2/lib/rake/task.rb:243:in `each'
/var/lib/gems/2.1.0/gems/rake-11.2.2/lib/rake/task.rb:243:in `execute'
/var/lib/gems/2.1.0/gems/rake-11.2.2/lib/rake/task.rb:187:in `block in invoke_with_call_chain'
/usr/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize'
/var/lib/gems/2.1.0/gems/rake-11.2.2/lib/rake/task.rb:180:in `invoke_with_call_chain'
/var/lib/gems/2.1.0/gems/rake-11.2.2/lib/rake/task.rb:173:in `invoke'
/var/lib/gems/2.1.0/gems/rake-11.2.2/lib/rake/application.rb:152:in `invoke_task'
/var/lib/gems/2.1.0/gems/rake-11.2.2/lib/rake/application.rb:108:in `block (2 levels) in top_level'
/var/lib/gems/2.1.0/gems/rake-11.2.2/lib/rake/application.rb:108:in `each'
/var/lib/gems/2.1.0/gems/rake-11.2.2/lib/rake/application.rb:108:in `block in top_level'
/var/lib/gems/2.1.0/gems/rake-11.2.2/lib/rake/application.rb:117:in `run_with_threads'
/var/lib/gems/2.1.0/gems/rake-11.2.2/lib/rake/application.rb:102:in `top_level'
/var/lib/gems/2.1.0/gems/rake-11.2.2/lib/rake/application.rb:80:in `block in run'
/var/lib/gems/2.1.0/gems/rake-11.2.2/lib/rake/application.rb:178:in `standard_exception_handling'
/var/lib/gems/2.1.0/gems/rake-11.2.2/lib/rake/application.rb:77:in `run'
/var/lib/gems/2.1.0/gems/rake-11.2.2/exe/rake:27:in `<top (required)>'
/usr/local/bin/rake:23:in `load'
/usr/local/bin/rake:23:in `<main>'
Tasks: TOP => mutant

如果我尝试直接执行，则会出现相同的消息

ytg@debian-vm:~/projects/new_project$ mutant -I lib/ --use rspec MyProject*
warning: parser/current is loading parser/ruby21, which recognizes
warning: 2.1.8-compliant syntax, but you are running 2.1.5.
warning: please see https://github.com/whitequark/parser#compatibility-with-ruby-mri.
Could not load integration "rspec" (you may want to try installing the gem mutant-rspec)

据我了解，这是因为some loading issue。但究竟是什么加载问题？如何在我的项目上运行 mutant？

（我也尝试使用sudo gem install mutant-rspec 安装gem，以防万一，但没有帮助，我收到相同的错误消息。）

Answer 1

您正在运行的mutant 可能未在正确的环境中执行。请改用bundle exec mutant，这将确保您的Gemfile 中指定的那个与正确的一组宝石一起使用。

为了帮助调试，请使用which mutant 来确定正在调用哪个版本。 sudo gem install 应该不是解决方案，我建议sudo gem uninstall 恢复到原来的位置，否则以后可能会出现问题。

但我认为所有这些都是红鲱鱼。

对于您的Rakefile，它实际上并不是针对mutant 脚本。你绕过它直接去Mutant::CLI。这里的问题是没有设置加载路径以使其包含mutant-rspec：

task :mutant do
  puts $LOAD_PATH # debug: see it's missing load path for mutant-rspec
  require 'bundler/setup' # This line is new
  puts $LOAD_PATH # debug: see how it changes

  result = Mutant::CLI.run %w(--since problem9 -Ilib -Ispec
                              --use rspec MyProject*)
  raise 'Mutation testing failed' unless result
end

或者，bundle exec rake mutant 也应该做同样的事情。我建议始终使用bundle exec（或binstubs），而不是使用rake 碰巧在您的路径上。否则很难推理。