php7-pdo_mysql package doesn't declare proper dependencies
With all of the moving around from php7.1 to php7 on edge, looks like pdo_mysql doesn’t add the proper .so files. Caught it when a composer install started complaining about missing extension files. Had to add the following into my apk update Docker RUN cmd:
php7-pdo@testing php7-mysqli@testing php7-mysqlnd@testing
to get things working again. mysqli might be a dep somewhere else but pdo and mysqlnd definitely need to be pulled automagically when the mysql PDO package is requested.
(from redmine: issue id 7109, created on 2017-04-10, closed on 2017-05-22)