wp-cli/wp-cli — pull request #1076 by danielbachhuber (2014-03-19 20:21:41+00:00)
Title: Clear `is_blog_installed` cache before checking

Core utilizes the object cache when checking `is_blog_installed()`. However,
when a persistent object cache is hooked up to the site, `is_blog_installed()`
can return the ghost of a previous WordPress install.