It is not a bug. GNU/Linux works properly and follow the standard:
RFC DOMAIN NAMES - CONCEPTS AND FACILITIES
tools.ietf.org/html/rfc1034
"The labels must follow the rules for ARPANET host names. They must
start with a letter, end with a letter or digit, and have as interior
characters only letters, digits, and hyphen. There are also some
restrictions on the length. Labels must be 63 characters or less."
It is not a bug. GNU/Linux works properly and follow the standard:
RFC DOMAIN NAMES - CONCEPTS AND FACILITIES
tools.ietf. org/html/ rfc1034
"The labels must follow the rules for ARPANET host names. They must
start with a letter, end with a letter or digit, and have as interior
characters only letters, digits, and hyphen. There are also some
restrictions on the length. Labels must be 63 characters or less."