新学 watir 的小白，正常运行一段时间后，就会报错，不用 thread 也一样，请各位大神指导一下

代码如下：

def get_post_link_by_slice(page_slice)
  b = Watir::Browser.new :phantomjs

  page_slice.each do |page|
  ┆ b.goto page

  ┆ links = b.ul(class: "text-list").lis
  ┆ links.each do |li|
  ┆ ┆ link = li.a.href
  ┆ ┆ if link.end_with?('html') && link.include?('trsyw')
  ┆ ┆ ┆ puts "#{page} #{link}"
  ┆ ┆ end
  ┆ end
  end

  b.close
end

pages = get_pages()

threads = []
pages.each_slice(300) do |s|
  threads << Thread.new do
  ┆ get_post_link_by_slice(s)
  end
end

threads.each { |t| t.join }

报错如下：

/Users/tanagisa/.rbenv/versions/2.4.1/lib/ruby/2.4.0/net/protocol.rb:176:in `rbuf_fill': Net::ReadTimeout (Net::ReadTimeout)
    from /Users/tanagisa/.rbenv/versions/2.4.1/lib/ruby/2.4.0/net/protocol.rb:154:in `readuntil'
    from /Users/tanagisa/.rbenv/versions/2.4.1/lib/ruby/2.4.0/net/protocol.rb:164:in `readline'
    from /Users/tanagisa/.rbenv/versions/2.4.1/lib/ruby/2.4.0/net/http/response.rb:40:in `read_status_line'
    from /Users/tanagisa/.rbenv/versions/2.4.1/lib/ruby/2.4.0/net/http/response.rb:29:in `read_new'
    from /Users/tanagisa/.rbenv/versions/2.4.1/lib/ruby/2.4.0/net/http.rb:1446:in `block in transport_request'
    from /Users/tanagisa/.rbenv/versions/2.4.1/lib/ruby/2.4.0/net/http.rb:1443:in `catch'
    from /Users/tanagisa/.rbenv/versions/2.4.1/lib/ruby/2.4.0/net/http.rb:1443:in `transport_request'
    from /Users/tanagisa/.rbenv/versions/2.4.1/lib/ruby/2.4.0/net/http.rb:1416:in `request'
    from /Users/tanagisa/.rbenv/versions/2.4.1/lib/ruby/2.4.0/net/http.rb:1409:in `block in request'
    from /Users/tanagisa/.rbenv/versions/2.4.1/lib/ruby/2.4.0/net/http.rb:877:in `start'
    from /Users/tanagisa/.rbenv/versions/2.4.1/lib/ruby/2.4.0/net/http.rb:1407:in `request'
    from /Users/tanagisa/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/selenium-webdriver-3.5.2/lib/selenium/webdriver/remote/http/default.rb:124:in `response_for'
    from /Users/tanagisa/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/selenium-webdriver-3.5.2/lib/selenium/webdriver/remote/http/default.rb:78:in `request'
    from /Users/tanagisa/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/selenium-webdriver-3.5.2/lib/selenium/webdriver/remote/http/common.rb:61:in `call'
    from /Users/tanagisa/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/selenium-webdriver-3.5.2/lib/selenium/webdriver/remote/bridge.rb:170:in `execute'
    from /Users/tanagisa/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/selenium-webdriver-3.5.2/lib/selenium/webdriver/remote/oss/bridge.rb:581:in `execute'
    from /Users/tanagisa/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/selenium-webdriver-3.5.2/lib/selenium/webdriver/remote/oss/bridge.rb:52:in `get'
    from /Users/tanagisa/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/selenium-webdriver-3.5.2/lib/selenium/webdriver/common/navigation.rb:32:in `to'
    from /Users/tanagisa/.rbenv/versions/2.4.1/lib/ruby/gems/2.4.0/gems/watir-6.8.4/lib/watir/browser.rb:82:in `goto'
    from test.rb:41:in `block in get_post_link_by_slice'
    from test.rb:40:in `each'
    from test.rb:40:in `get_post_link_by_slice'
    from test.rb:60:in `block in <main>'
    from test.rb:58:in `each_slice'
    from test.rb:58:in `with_index'
    from test.rb:58:in `<main>'