Fix idempotency issues in build_essential on the mac

2 issues this solves:

- On some systems the Command Line Tools aren't showing up in the install history plist we're parsing. This means we attempt to install the tools each time chef runs, which takes a LONG time even on a top of the line mac. It was suggested in mac admins slack to just use xcode-select -p which lists the command line tools path or exits 2 if not installed.

- When the :upgrade action is used we were parsing out the software update list twice for no reason, which made it take even longer.

Signed-off-by: Tim Smith <tsmith@chef.io>

1 files changed, 5 insertions, 8 deletions

diff --git a/lib/chef/resource/build_essential.rb b/lib/chef/resource/build_essential.rb
index 17b97ebd97..3039f709c8 100644
--- a/lib/chef/resource/build_essential.rb
+++ b/lib/chef/resource/build_essential.rb
@@ -15,7 +15,6 @@
 #
 
 require_relative "../resource"
-autoload :Plist, "plist"
 
 class Chef
   class Resource
@@ -130,8 +129,8 @@ class Chef
           pkg_label = xcode_cli_package_label
 
           # With upgrade action we should install if it's not installed or if there's an available update.
-          # `xcode_cli_package_label` will be nil if there's no update.
-          install_xcode_cli_tools(pkg_label) if !xcode_cli_installed? || xcode_cli_package_label
+          # `pkg_label` will be nil if there's no update.
+          install_xcode_cli_tools(pkg_label) if !xcode_cli_installed? || pkg_label
         else
           Chef::Log.info "The build_essential resource :upgrade action is only supported on macOS systems. Skipping..."
         end
@@ -160,14 +159,12 @@ class Chef
         end
 
         #
-        # Determine if the XCode Command Line Tools are installed by parsing the install history plist.
-        # We parse the plist data install of running pkgutil because we found that pkgutils doesn't always contain all the packages
+        # Determine if the XCode Command Line Tools are installed by checking
+        # for success from `xcode-select -p`
         #
         # @return [true, false]
         def xcode_cli_installed?
-          packages = ::Plist.parse_xml(::File.open("/Library/Receipts/InstallHistory.plist", "r"))
-          packages.select! { |package| package["displayName"].match? "Command Line Tools" }
-          !packages.empty?
+          !shell_out("xcode-select", "-p").error?
         end
 
         #