Prevent Puppet's autoloader from double-loading files from older installed
openvox gem versions during testing.

Puppet::Util::Autoload#search_directories returns:
  gem_directories + $LOAD_PATH
where gem_directories is built from Gem::Specification.stubs -- every
installed gem's lib/, unconditionally. When a previous openvox version is
installed, its lib/ ends up in search_directories alongside the source
tree's lib/, so the autoloader (which uses Kernel.load, not require) loads
the same file twice, causing constant redefinitions and:
  ArgumentError: Indirection file_metadata is already defined

Fix: filter openvox entries out of Gem::Specification.stubs before
requiring puppet, so only the source tree's lib/ (already on $LOAD_PATH
via rspec) is visible to the autoloader.

Also pre-require 'scanf' so it is already in $LOADED_FEATURES before
Puppet function definitions are eval'd.  The scanf function's definition
block calls require 'scanf' inside a class_eval context; pre-loading it
here ensures it resolves correctly regardless of the eval binding context.

--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -14,3 +14,20 @@ rescue LoadError
 end
 
+# Puppet's autoloader searches lib/ dirs of ALL installed gems via
+# Gem::Specification.stubs. When upgrading, the previously-installed openvox
+# gem would otherwise be found alongside the source tree, causing Kernel.load
+# to define the same constants twice and produce "Indirection already defined".
+if defined?(Gem)
+  original_stubs = Gem::Specification.method(:stubs)
+  Gem::Specification.define_singleton_method(:stubs) do |*args|
+    original_stubs.call(*args).reject { |spec| spec.name == 'openvox' }
+  end
+end
+
+# Pre-load scanf so require 'scanf' inside Puppet function class_eval works.
+begin
+  require 'scanf'
+rescue LoadError
+end
+
 require 'puppet'