[php] Warning: "continue" targeting switch is equivalent to "break". Did you mean to use "continue 2"?

@aimme's answer should be accepted!

I would extend his answer with @david-baucum's comment because his explanation is clear!

I would also extend his answer that you can run multiple PHP versions at the same time using ppa:ondrej/php.

Then you don't need to change the PHP version simple call the composer like this: /usr/bin/php7.2 /usr/local/bin/composer install