providers/virtualbox: retry list hostonlyifs [GH-2831]

CHANGELOG.md

@@ -63,6 +63,8 @@ BUG FIXES:
   - hosts/bsd: Don't invoke shell for NFS sudo calls. [GH-2808]
   - providers/virtualbox: Enabling internal networks by just setting "true"
     works properly. [GH-2751]
+  - providers/virtualbox: Make more internal interactions with VBoxManage
+    retryable to avoid spurious VirtualBox errors. [GH-2831]
   - provisioners/chef: When chowning folders, don't follow symlinks.
   - provisioners/salt: Options can now set install type and install args.
     [GH-2766]

plugins/providers/virtualbox/driver/version_4_3.rb

@@ -68,7 +68,7 @@ module VagrantPlugins
 
         def delete_unused_host_only_networks
           networks = []
-          execute("list", "hostonlyifs").split("\n").each do |line|
+          execute("list", "hostonlyifs", retryable: true).split("\n").each do |line|
             networks << $1.to_s if line =~ /^Name:\s+(.+?)$/
           end
 
@@ -338,7 +338,7 @@ module VagrantPlugins
             dhcp[info[:network]] = info
           end
 
-          execute("list", "hostonlyifs", :retryable => true).split("\n\n").collect do |block|
+          execute("list", "hostonlyifs", retryable: true).split("\n\n").collect do |block|
             info = {}
 
             block.split("\n").each do |line|
@@ -521,7 +521,7 @@ module VagrantPlugins
         def verify!
           # This command sometimes fails if kernel drivers aren't properly loaded
           # so we just run the command and verify that it succeeded.
-          execute("list", "hostonlyifs")
+          execute("list", "hostonlyifs", retryable: true)
         end
 
         def verify_image(path)