[#179] Catch failure to get uptime from device

Netdisco/Changes

@@ -4,6 +4,10 @@
 
   * [#171] Log files now rotate at 10MB up to seven times
 
+  [ENHANCEMENTS]
+
+  * [#179] Catch failure to get uptime from device
+
   [BUG FIXES]
 
   * Another fix for NetAddr::MAC tripping up on v6 addresses

Netdisco/lib/App/Netdisco/Core/Discover.pm

@@ -220,6 +220,11 @@ sub store_interfaces {
 
   # clear the cached uptime and get a new one
   my $dev_uptime = $snmp->load_uptime;
+  if (!defined $dev_uptime) {
+      error sprintf ' [%s] interfaces - Error! Failed to get uptime from device!',
+        $device->ip;
+      return;
+  }
 
   # used to track how many times the device uptime wrapped
   my $dev_uptime_wrapped = 0;