Fix handling using resources with incompatible resources (eg file + aws).

Signed-off-by: Ryan Davis <zenspider@chef.io>

lib/inspec/resources/file.rb

@@ -165,7 +165,11 @@ module Inspec::Resources
     end
 
     def to_s
-      "File #{source_path}"
+      if file then
+        "File #{source_path}"
+      else
+        "Bad File on %s" % [inspec.backend.class]
+      end
     end
 
     private

test/functional/inspec_exec_test.rb

@@ -23,6 +23,15 @@ describe "inspec exec" do
     skip_windows!
   end
 
+  it "cleanly fails if mixing incompatible resource and transports" do
+    # TODO: I do not know how to test this more directly. It should be possible.
+    inspec "exec -t aws:// #{profile_path}/incompatible_resource_for_transport.rb"
+
+    stdout.must_include "Bad File on TrainPlugins::Aws::Connection"
+    stdout.must_include "Resource `file` is not supported on platform aws/train-aws"
+    stderr.must_equal ""
+  end
+
   it "can execute the profile" do
     inspec("exec " + example_profile + " --no-create-lockfile")
     stderr.must_equal ""

test/unit/mock/profiles/incompatible_resource_for_transport.rb

@@ -0,0 +1,3 @@
+describe file('/tmp/foo') do
+  it { should exist }
+end