wp-cli/wp-cli — pull request #909 by scribu (2013-12-17 23:23:55+00:00)
Title: `wp core is-installed` breaks on multisite

Related to #730, `wp-includes/ms-settings.php` uses `$_SERVER['HTTP_HOST']`, and thus causes warnings. In turn, this makes PHP return a `0` status code (sigh).

Looks like we also have to set `WP_INSTALLING` to be able to get past the `die()` calls.