How do I set root password for mysql 5.7 on netbsd

Question

I'm trying to get mySQL 5.7 working on NetBSD (unix). When I try "mysql -u root" I get

ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

When I try "mysqld --initialize-insecure" I get

[ERROR] --initialize specified but the data directory has files in it.

What do I do?