diff -r 8371c99c7947 -r 240ca282331d dev/provisioning/modules/drush/manifests/cacheclear.pp
--- a/dev/provisioning/modules/drush/manifests/cacheclear.pp	Thu Nov 10 02:01:46 2016 +0100
+++ b/dev/provisioning/modules/drush/manifests/cacheclear.pp	Thu Nov 10 14:07:02 2016 +0100
@@ -9,6 +9,7 @@
   # Clear drush cache on demand.
   exec { 'drush-cc-drush':
     command     => "${drush::drush_exe_default} cc drush",
+    environment => ["DRUSH_PHP=${drush::drush_php}"],
     require     => File[$drush::drush_exe_default],
     refreshonly => true,
   }