While working on reproducible builds for openSUSE, I found that
our libguestfs package can produce bit-identical results locally,
but when comparing with the official OBS builds,
it has this diff in 

--- old//usr/lib64/guestfs/supermin.d/base.tar.gz/./etc/hosts
+++ new//usr/lib64/guestfs/supermin.d/base.tar.gz/./etc/hosts
@@ -1,4 +1,26 @@ 
 127.0.0.1 hst   
+#               
+# hosts         This file describes a number of hostname-to-address
+#               mappings for the TCP/IP subsystem.  It is mostly
+#               used at boot time, when no name servers are running.
+#               On small systems, this file can be used instead of a
+#               "named" name server.
+# Syntax:
+#
+# IP-Address  Full-Qualified-Hostname  Short-Hostname
+#
+
 127.0.0.1 hst
+# fallback hostname used by NetworkManager
 127.0.0.1 hst
-127.0.0.1 hst   
+
+# special IPv6 addresses
+::1             localhost ipv6-localhost ipv6-loopback
+
+fe00::0         ipv6-localnet
+
+ff00::0         ipv6-mcastprefix
+ff02::1         ipv6-allnodes
+ff02::2         ipv6-allrouters
+ff02::3         ipv6-allhosts
+


Chances are, that it pulls in the /etc/hosts file from the build VM
and that one might vary depending from usage of a preinstallimage or other factors.