Let us add this workaround that works on my laptop!
Mac with Osx Mojave 10.14.5
Mysql 8.0.17 was installed with homebrew
I run the following command to locate the path of mysql
brew info mysql
Once the path is known, I run this :
/usr/local/Cellar/mysql/8.0.17/bin/mysqld_safe --skip-grant-table
In another terminal I run :
mysql -u root
Inside that terminal, I changed the root password using :
update mysql.user set authentication_string='NewPassword' where user='root';
and to finish I run :
FLUSH PRIVILEGES;
And voila the password was reset.