Detect missing Linux kexts via vboxnetctl error message [GH-1671]

CHANGELOG.md

@@ -4,6 +4,8 @@ IMPROVEMENTS:
 
   - Better VBoxManage error detection on Windows systems. This avoids
     some major issues where Vagrant would sometimes "lose" your VM. [GH-1669]
+  - Better detection of missing VirtualBox kernel drivers on Linux
+    systems. [GH-1671]
 
 ## 1.2.2 (April 23, 2013)
 

plugins/providers/virtualbox/driver/base.rb

@@ -303,7 +303,16 @@ module VagrantPlugins
               # Sometimes, VBoxManage fails but doesn't actual return a non-zero
               # exit code. For this we inspect the output and determine if an error
               # occurred.
+
+              if r.stderr =~ /failed to open \/dev\/vboxnetctl/i
+                # This catches an error message that only shows when kernel
+                # drivers aren't properly installed.
+                @logger.error("Error message about unable to open vboxnetctl")
+                raise Vagrant::Errors::VirtualBoxKernelModuleNotLoaded
+              end
+
               if r.stderr =~ /VBoxManage([.a-z]+?): error:/
+                # This catches the generic VBoxManage error case.
                 @logger.info("VBoxManage error text found, assuming error.")
                 errored = true
               end

templates/locales/en.yml

@@ -528,8 +528,8 @@ en:
         %{supported_versions}
       virtualbox_kernel_module_not_loaded: |-
         VirtualBox is complaining that the kernel module is not loaded. Please
-        run `VBoxManage --version` to see the error message which should contain
-        instructions on how to fix this error.
+        run `VBoxManage --version` or open the VirtualBox GUI to see the error
+        message which should contain instructions on how to fix this error.
       virtualbox_install_incomplete: |-
         VirtualBox is complaining that the installation is incomplete. Please
         run `VBoxManage --version` to see the error message which should contain