Require and use 'posix/spawn' when running ruby 1.8 without using For…

…eman.ruby_18? (which is the subject under test).

spec/spec_helper.rb

@@ -10,6 +10,15 @@
 
 $:.unshift File.expand_path("../../lib", __FILE__)
 
+begin
+  def running_ruby_18?
+    defined?(RUBY_VERSION) and RUBY_VERSION =~ /^1\.8\.\d+/
+  end
+  require 'posix/spawn' if running_ruby_18?
+rescue LoadError
+  STDERR.puts "WARNING: foreman requires gem `posix-spawn` on Ruby #{RUBY_VERSION}. Please `gem install posix-spawn`."
+end
+
 def mock_export_error(message)
   lambda { yield }.should raise_error(Foreman::Export::Exception, message)
 end
@@ -36,8 +45,7 @@ def foreman(args)
 
 def forked_foreman(args)
   rd, wr = make_pipe
-  if Foreman.jruby_18? || Foreman.ruby_18?
-    require 'posix/spawn'
+  if running_ruby_18?
     POSIX::Spawn.spawn({}, "bundle exec bin/foreman #{args}", :out => wr, :err => wr)
   else
     Process.spawn("bundle exec bin/foreman #{args}", :out => wr, :err => wr)
@@ -66,8 +74,7 @@ def fork_and_capture(&blk)
 end
 
 def fork_and_get_exitstatus(args)
-  pid = if Foreman.jruby_18? || Foreman.ruby_18?
-    require 'posix/spawn'
+  pid = if running_ruby_18?
     POSIX::Spawn.spawn({}, "bundle exec bin/foreman #{args}", :out => "/dev/null", :err => "/dev/null")
   else
     Process.spawn("bundle exec bin/foreman #{args}", :out => "/dev/null", :err => "/dev/null")
@@ -170,4 +177,5 @@ def capture_stdout
   config.order = 'rand'
   config.include FakeFS::SpecHelpers, :fakefs
   config.mock_with :rr
+  config.backtrace_clean_patterns = []
 end