fix(misc): Handle cache unpickling failure in release check

Guard `cache.get('latest_release')` during release checks to prevent a
500 when stale cached data can't be unpickled after dependency upgrades.
On failure, log at debug level and delete the affected cache key.

Fixes #21254

netbox/dcim/models/device_components.py

@@ -732,25 +732,6 @@ class BaseInterface(models.Model):
         if self.primary_mac_address:
             return self.primary_mac_address.mac_address
 
-    @property
-    def mac_address_display(self):
-        """
-        Rich representation of MAC addresses for use in table columns (e.g. InterfaceTable).
-        Handles various configurations of MAC addresses for an interface:
-        11:22:33:44:55:66      <-- Single MAC address on interface, assigned as primary
-        11:22:33:44:55:66 (2)  <-- Multiple MAC addresses on interface, one assigned as primary
-        2 available            <-- 1 or more MAC addresses on interface, none assigned as primary
-        -                      <-- No MAC addresses on interface
-        """
-        available_mac_count = self.mac_addresses.count()
-        if self.primary_mac_address:
-            if available_mac_count > 1:
-                return f"{self.primary_mac_address} ({available_mac_count})"
-            return self.primary_mac_address
-        if available_mac_count:
-            return f"{available_mac_count} available"
-        return None
-
 
 class Interface(
     InterfaceValidationMixin,

netbox/dcim/tables/devices.py

@@ -616,7 +616,6 @@ class BaseInterfaceTable(NetBoxTable):
     )
     primary_mac_address = tables.Column(
         verbose_name=_('MAC Address'),
-        accessor=Accessor('mac_address_display'),
         linkify=True
     )
 

netbox/extras/events.py

@@ -86,7 +86,7 @@ def enqueue_event(queue, instance, request, event_type):
 
 
 def process_event_rules(event_rules, object_type, event_type, data, username=None, snapshots=None, request=None):
-    user = User.objects.get(username=username) if username else None
+    user = None  # To be resolved from the username if needed
 
     for event_rule in event_rules:
 
@@ -134,6 +134,10 @@ def process_event_rules(event_rules, object_type, event_type, data, username=Non
             # Resolve the script from action parameters
             script = event_rule.action_object.python_class()
 
+            # Retrieve the User if not already resolved
+            if user is None:
+                user = User.objects.get(username=username)
+
             # Enqueue a Job to record the script's execution
             from extras.jobs import ScriptJob
             params = {

netbox/netbox/views/misc.py

@@ -1,5 +1,6 @@
 import re
 from collections import namedtuple
+import logging
 
 from django.conf import settings
 from django.contrib import messages
@@ -28,6 +29,8 @@ __all__ = (
     'SearchView',
 )
 
+logger = logging.getLogger(f'netbox.{__name__}')
+
 Link = namedtuple('Link', ('label', 'viewname', 'permission', 'count'))
 
 
@@ -50,7 +53,14 @@ class HomeView(ConditionalLoginRequiredMixin, View):
         # Check whether a new release is available. (Only for superusers.)
         new_release = None
         if request.user.is_superuser:
-            latest_release = cache.get('latest_release')
+            # cache.get() can raise if the cached value can't be unpickled after dependency upgrades
+            try:
+                latest_release = cache.get('latest_release')
+            except Exception:
+                logger.debug("Failed to read 'latest_release' from cache; deleting key", exc_info=True)
+                cache.delete('latest_release')
+                latest_release = None
+
             if latest_release:
                 release_version, release_url = latest_release
                 if release_version > version.parse(settings.RELEASE.version):

netbox/templates/dcim/interface.html

@@ -143,11 +143,9 @@
           <tr>
             <th scope="row">{% trans "MAC Address" %}</th>
             <td>
-              {% if object.mac_address_display %}
-                <span class="font-monospace">{{ object.mac_address_display|linkify }}</span>
-                {% if object.primary_mac_address %}
-                  <span class="badge text-bg-primary">{% trans "Primary" %}</span>
-                {% endif %}
+              {% if object.primary_mac_address %}
+                <span class="font-monospace">{{ object.primary_mac_address|linkify }}</span>
+                <span class="badge text-bg-primary">{% trans "Primary" %}</span>
               {% else %}
                 {{ ''|placeholder }}
               {% endif %}

netbox/templates/virtualization/vminterface.html

@@ -78,11 +78,9 @@
         <tr>
           <th scope="row">{% trans "MAC Address" %}</th>
           <td>
-            {% if object.mac_address_display %}
-              <span class="font-monospace">{{ object.mac_address_display|linkify }}</span>
-              {% if object.primary_mac_address %}
-                <span class="badge text-bg-primary">{% trans "Primary" %}</span>
-              {% endif %}
+            {% if object.mac_address %}
+              <span class="font-monospace">{{ object.mac_address }}</span>
+              <span class="badge text-bg-primary">{% trans "Primary" %}</span>
             {% else %}
               {{ ''|placeholder }}
             {% endif %}