running `composer update` or `php artisan` return error

When I run composer update or php artisan I get this error:

{"error":{"type":"ErrorException","message":"mkdir(): No such file or directory","file":"\/var\/www\/html_new\/vendor\/laravel\/framework\/src\/Illuminate\/Filesystem\/Filesystem.php","line":297}}

If I echo out $path in this function within Filesystem.php it returns NULL.

I've tried:

• Deleting vendor and rerunning composer update
• Checking permissions of app/storage
• Running composer clear-cache
• Running composer diagnose to make sure my composer.json file is legit

Any ideas of why this might be happening and how I can fix it?