diff --git a/ansible/fatimage.yml b/ansible/fatimage.yml
index 0764477b3..7c44c1759 100644
--- a/ansible/fatimage.yml
+++ b/ansible/fatimage.yml
@@ -1,24 +1,22 @@
 # Builder version of site.yml just installing binaries
 
-- hosts: builder
-  become: no
-  gather_facts: no
-  tasks:
-    - name: Report hostname (= final image name)
-      command: hostname
-
 - name: Run pre.yml hook
   vars:
-    appliances_environment_root: "{{ lookup('env', 'APPLIANCES_ENVIRONMENT_ROOT') }}"
+    # hostvars not available here, so have to recalculate environment root:
+    appliances_environment_root: "{{ ansible_inventory_sources | last | dirname }}"
     hook_path: "{{ appliances_environment_root }}/hooks/pre.yml"
   import_playbook: "{{ hook_path if hook_path | exists else 'noop.yml' }}"
   when: hook_path | exists
 
+- import_playbook: validate.yml
+  when: appliances_validate | default(true)
+
 - import_playbook: bootstrap.yml
 
 - name: Run post-bootstrap.yml hook
   vars:
-    appliances_environment_root: "{{ lookup('env', 'APPLIANCES_ENVIRONMENT_ROOT') }}"
+    # hostvars not available here, so have to recalculate environment root:
+    appliances_environment_root: "{{ ansible_inventory_sources | last | dirname }}"
     hook_path: "{{ appliances_environment_root }}/hooks/post-bootstrap.yml"
   import_playbook: "{{ hook_path if hook_path | exists else 'noop.yml' }}"
   when: hook_path | exists
@@ -34,7 +32,7 @@
         tasks_from: client-install.yml
       when: "'freeipa_client' in group_names"
 
-    # - import_playbook: filesystems.yml:
+    # import_playbook: filesystems.yml:
     - name: Install nfs packages
       dnf:
         name: nfs-utils
@@ -51,7 +49,7 @@
   become: yes
   gather_facts: yes
   tasks:
-    # - import_playbook: slurm.yml:
+    # import_playbook: slurm.yml:
     - name: Setup DB
       include_role:
         name: mysql
@@ -73,7 +71,7 @@
         name: openondemand
         tasks_from: vnc_compute.yml
 
-    # - import_playbook: monitoring.yml:
+    # import_playbook: monitoring.yml:
     - import_role:
         name: opensearch
         tasks_from: install.yml
@@ -159,18 +157,20 @@
 
 - name: Run post.yml hook
   vars:
-    appliances_environment_root: "{{ lookup('env', 'APPLIANCES_ENVIRONMENT_ROOT') }}"
+    # hostvars not available here, so have to recalculate environment root:
+    appliances_environment_root: "{{ ansible_inventory_sources | last | dirname }}"
     hook_path: "{{ appliances_environment_root }}/hooks/post.yml"
   import_playbook: "{{ hook_path if hook_path | exists else 'noop.yml' }}"
   when: hook_path | exists
 
-- hosts: builder
-  become: yes
+- name: Clean up and shutdown Packer VM
+  hosts: builder
   gather_facts: no
+  become: yes
   tasks:
-    # - meta: end_here
     - name: Cleanup image
       import_tasks: cleanup.yml
-
     - name: Shutdown Packer VM
-      community.general.shutdown:
+    community.general.shutdown:
+
+...
\ No newline at end of file
diff --git a/ansible/site.yml b/ansible/site.yml
index bb379399d..d72c29d8b 100644
--- a/ansible/site.yml
+++ b/ansible/site.yml
@@ -36,12 +36,4 @@
   import_playbook: "{{ hook_path if hook_path | exists else 'noop.yml' }}"
   when: hook_path | exists
 
-- name: Clean up and shutdown Packer VM
-  hosts: builder
-  gather_facts: no
-  become: yes
-  tasks:
-    - import_tasks: cleanup.yml
-    - community.general.shutdown:
-
 ...
\ No newline at end of file
diff --git a/environments/.stackhpc/hooks/pre.yml b/environments/.stackhpc/hooks/pre.yml
index 8e6f0e25e..c1bab2a1c 100644
--- a/environments/.stackhpc/hooks/pre.yml
+++ b/environments/.stackhpc/hooks/pre.yml
@@ -1,3 +1,10 @@
+- hosts: builder
+  become: no
+  gather_facts: no
+  tasks:
+    - name: Report hostname (= final image name)
+      command: hostname
+
 - hosts: control:!builder
   become: yes
   gather_facts: false
diff --git a/environments/common/inventory/group_vars/builder/defaults.yml b/environments/common/inventory/group_vars/builder/defaults.yml
index 7c4ea5712..b5a37bf78 100644
--- a/environments/common/inventory/group_vars/builder/defaults.yml
+++ b/environments/common/inventory/group_vars/builder/defaults.yml
@@ -16,3 +16,4 @@ opensearch_state: stopped # avoid writing config+certs+db into image
 cuda_persistenced_state: stopped # probably don't have GPU in Packer build VMs
 firewalld_enabled: false # dnf install of firewalld enables it
 firewalld_state: stopped
+appliances_validate: false