Moving wp-content outside of the WordPress application directory on localhost.

I’m trying to setup a new install of WordPress on my local machine that I am going to be managing with Git. I want to manage repos for the WordPress Core, Plugins, and Themes all separately (including a repo for my own child-theme) using Git submodules. Because of that, I need to have index.php, wp-config.php and the wp-content directories outside of the WordPress application directory. I’m following the instructions here. But when I go to https://localhost/projectdir in my browser, I get a blank white screen. If I skip the steps about defining WP_SITEURL, WP_HOME, WP_CONTENT_DIR, and WP_CONTENT_URL in wp-config.php, and just set the first two in the database, it works fine. But if I try to set any of them in the config file, I get a blank screen. If I type ‘localhost’ explicitly instead of using $_SERVER[‘SERVER_NAME’] I get the exact same results. I tried a few different things; if I set WP_SITEURL and WP_HOME in the database, and WP_CONTENT_DIR in wp-config.php, I get a blank white homepage at https://localhost/projectdir but I can login to the dashboard and see all of the plugins in my external wp-content directory listed there. That’s the closest I’ve gotten.

Any help would be greatly appreciated!