Don't clear NFS exports on expected failure [GH-577]

CHANGELOG.md

@@ -50,6 +50,7 @@
   - `vagrant ssh -c` will now send stderr to stderr and stdout to stdout
     on the host machine, instead of all output to stdout.
   - Vagrant can now be interrupted during the "importing" step.
+  - NFS exports will no longer be cleared when an expected error occurs. [GH-577]
 
 ## 0.8.10 (December 10, 2011)
 

lib/vagrant/action/vm/nfs.rb

@@ -42,7 +42,12 @@ module Vagrant
         end
 
         def recover(env)
-          clear_nfs_exports(env) if env[:vm].created?
+          # Ignore any VagrantErrors, because they were expected and
+          # will cause the VM to stick around.
+          return if env["vagrant.error"].is_a?(Errors::VagrantError)
+
+          # Otherwise, clear the NFS exports.
+          clear_nfs_exports(env)
         end
 
         # Returns the folders which are to be synced via NFS.