我正在尝试通过插入控制台在fluentD项目中执行单元测试：
bundle exec rake test test/plugin/test_out_foo.rb
但它返回以下内容：
fatal: Not a git repository (or any parent up to mount point
/var/lib/gems/2.3.0/gems/fluentd-0.12.40)
Stopping at filesystem boundary (GIT_DISCOVERY_ACROSS_FILESYSTEM not set).
Could not find gem 'parallel_tests (~> 0.15.3)' in any of the gem sources
listed in your Gemfile.
Run `bundle install` to install missing gems.
我并不担心“不是git存储库”，因为我读到它并不会影响这个测试的结果。然后，如果我尝试按照建议进入“捆绑安装”，则返回：
Installing cool.io 1.5.1 with native extensions
Gem::Ext::BuildError: ERROR: Failed to build gem native extension.
current directory: /var/lib/gems/2.3.0/gems/fluentd-
0.12.40/vendor/bundle/ruby/2.3.0/gems/cool.io-1.5.1/ext/cool.io
/usr/bin/ruby2.3 -r ./siteconf20170928-2385-ss02z5.rb extconf.rb
checking for rb_thread_blocking_region()... no
...
checking for sys/event.h... no
checking for port.h... no
checking for sys/resource.h... yes
creating Makefile
To see why this extension failed to compile, please check the mkmf.log which
can be found here:
/var/lib/gems/2.3.0/gems/fluentd-
0.12.40/vendor/bundle/ruby/2.3.0/extensions/x86_64-linux/2.3.0/cool.io-
1.5.1/mkmf.log
...
Make sure that `gem install cool.io -v '1.5.1'` succeeds before bundling.
An error occurred while installing cool.io (1.5.1), and Bundler cannot
continue.
在mkmf.log中，第一个（但不仅仅是）错误是：
conftest.c:13:57: error: ‘rb_thread_blocking_region’ undeclared (first use
in this function)
int t(void) { void ((*volatile p)()); p = (void ((*)
()))rb_thread_blocking_region; return !p; }
如果我在控制台中输入'gem list'，它会显示parallel_tests（2.7.1）和cool.io（1.5.1），所以我不明白为什么会出现这些错误。
我也看到了这个链接https://github.com/phusion/passenger/issues/1314。使用动态libraby而不是静态libraby编译Ruby可以解决问题。但是，既然我安装了Ruby，我就不需要编译它，对吧？
操作系统是Ubuntu 16.04，Ruby版本是2.3.1，FluentD版本是0.12.40。
感谢您的帮助！