Comment 4 for bug 1850190

Next failure I got was:
+ chown mysql: /home/ubuntu/php7.3/php7.3-7.3.10/mysql_db
+ /usr/sbin/mysqld --no-defaults --skip-grant-tables --user=mysql --bind-address=127.0.0.1 --port=1636 --socket=/home/ubuntu/php7.3/php7.3-7.3.10/mysql_db/mysql.sock --datadir=/home/ubuntu/php7.3/php7.3-7.3.10/mysql_db/data --
initialize-insecure
mysqld: Can't create directory '/home/ubuntu/php7.3/php7.3-7.3.10/mysql_db/data/' (OS errno 13 - Permission denied)

The chown call failed, of course:
$ chown mysql: /home/ubuntu/php7.3/php7.3-7.3.10/mysql_db
chown: changing ownership of '/home/ubuntu/php7.3/php7.3-7.3.10/mysql_db': Operation not permitted

Let me check the other commits you mentioned.