Why does /usr/sbin/snap shows "Cannot open file reading: /proc/xxxxxx" when -v option is specified?

Issue

• Why does /usr/sbin/snap shows "Cannot open file reading: /proc/xxxxxx" when -v option is specified? Is this a bug?

#/usr/sbin/snap -av
/usr/sbin/snap: Cannot open file reading: /proc/ide
/usr/sbin/snap: Cannot open file reading: /proc/pci
/usr/sbin/snap: Cannot open file reading: /proc/ppc64/pci
/usr/sbin/snap: Cannot open file reading: /proc/sys/vm/compact_memory
/usr/sbin/snap: Cannot open file reading: /proc/sys/net/ipv4/route/flush
/usr/sbin/snap: Cannot open file reading: /etc/raidtab
/usr/sbin/snap: "servicelog --dump" returned 2
/usr/sbin/snap: "usysident" returned 254
output written to snap.tar.gz