Apex domains cannot have CNAME records.
Question and response
Question
dig skylinux.com. NS
Answer
skylinux.com. 4 NS ns1.skylinux.org.
skylinux.com. 4 NS ns.skylinux.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0