Handle REXML requires for Ubuntu focal

.github/workflows/unit-tests.yml

@@ -41,6 +41,12 @@ jobs:
           - ruby: 2.6.6
             vagrant: v2.2.14
             allow_fail: false
+          - ruby: 2.7.2
+            vagrant: v2.2.10
+            allow_fail: false
+            # above block is to ensure compatible with Ubuntu 20.04 vagrant package
+            # although it uses 2.2.10 it is the earliest version that will install on
+            # ruby 2.7 without patching
           - ruby: 3.0.0
             vagrant:
             allow_fail: false

lib/vagrant-libvirt/action/destroy_domain.rb

@@ -2,11 +2,8 @@
 
 require 'log4r'
 
-begin
-  require 'rexml'
-rescue LoadError
-  require 'rexml/rexml'
-end
+require 'rexml/document'
+require 'rexml/xpath'
 
 require 'vagrant-libvirt/util/domain_flags'
 

lib/vagrant-libvirt/action/resolve_disk_settings.rb

@@ -2,11 +2,8 @@
 
 require 'log4r'
 
-begin
-  require 'rexml'
-rescue LoadError
-  require 'rexml/rexml'
-end
+require 'rexml/document'
+require 'rexml/xpath'
 
 require 'vagrant-libvirt/util/resolvers'
 

lib/vagrant-libvirt/action/start_domain.rb

@@ -3,6 +3,8 @@
 require 'log4r'
 
 require 'rexml/document'
+require 'rexml/formatters/pretty'
+require 'rexml/xpath'
 
 require 'vagrant-libvirt/util/xml'
 

lib/vagrant-libvirt/util/compat.rb

@@ -11,7 +11,7 @@ module Util
       module Compat
         def self.action_hook_args(name, action)
           # handle different number of arguments for action_hook depending on vagrant version
-          if Gem::Version.new(Vagrant::VERSION) >= Gem::Version.new('2.2.11')
+          if Gem::Version.new(Vagrant::VERSION) >= Gem::Version.new('2.2.10')
             return name, action
           end