Vagrant2.2.6 和VirtualBox6.1.0不兼容问题解决办法

在安装完毕vagrant和virtualbox后，

执行命令

vagrant up时出现

No usable default provider could be found for your system.

Vagrant relies on interactions with 3rd party systems, known as
"providers", to provide Vagrant with resources to run development
environments. Examples are VirtualBox, VMware, Hyper-V.

The easiest solution to this message is to install VirtualBox, which
is available for free on all major platforms.

If you believe you already have a provider available, make sure it
is properly installed and configured. You can see more details about
why a particular provider isn't working by forcing usage with
`vagrant up --provider=PROVIDER`, which should give you a more specific
error message for that particular provider.
出现此错误提示未安装virtualbox，但实际已安装完毕。查资料发现存在版本兼容问题。但目前（今天2020.1.1）均是最新版本，后在github找到答案。

需要修改三处：

1、在/opt/vagrant/embedded/gems/2.2.6/gems/vagrant-2.2.6/plugins/providers/virtualbox/plugin.rb的文件内新增红色部分

module Driver
  autoload :Meta, File.expand_path("../driver/meta", __FILE__) autoload :Version_4_0, File.expand_path("../driver/version_4_0", __FILE__) autoload :Version_4_1, File.expand_path("../driver/version_4_1", __FILE__) autoload :Version_4_2, File.expand_path("../driver/version_4_2", __FILE__) autoload :Version_4_3, File.expand_path("../driver/version_4_3", __FILE__) autoload :Version_5_0, File.expand_path("../driver/version_5_0", __FILE__) autoload :Version_5_1, File.expand_path("../driver/version_5_1", __FILE__) autoload :Version_5_2, File.expand_path("../driver/version_5_2", __FILE__) autoload :Version_6_0, File.expand_path("../driver/version_6_0", __FILE__) autoload :Version_6_1, File.expand_path("../driver/version_6_1", __FILE__) end

2、在/opt/vagrant/embedded/gems/2.2.6/gems/vagrant-2.2.6/plugins/providers/virtualbox/driver/meta.rb的文件内新增红色部分

driver_map   = {
  "4.0" => Version_4_0,
  "4.1" => Version_4_1, "4.2" => Version_4_2, "4.3" => Version_4_3, "5.0" => Version_5_0, "5.1" => Version_5_1, "5.2" => Version_5_2, "6.0" => Version_6_0, "6.1" => Version_6_1, }

3、在/opt/vagrant/embedded/gems/2.2.6/gems/vagrant-2.2.6/plugins/providers/virtualbox/driver文件夹内新创建version_6_1.rb的文件，并在文件内添加如下信息：

require File.expand_path("../version_6_0", __FILE__)

module VagrantPlugins
  module ProviderVirtualBox
    module Driver
      # Driver for VirtualBox 6.1.x
      class Version_6_1 < Version_6_0
        def initialize(uuid)
          super

          @logger = Log4r::Logger.new("vagrant::provider::virtualbox_6_1")
        end
      end
    end
  end
end

通过一系列修改后，可以正常执行。