After removing the vendor directory to clear up a load of xdebug and debugging flags and reinstalling it like i'm used to I'm now greeted by this message:
 

 
When I run 
 
composer show magento/module-customer-balance
 
I get the following output
 
[InvalidArgumentException]
Package magento/module-customer-balance not found

 
Did somebody accidentally delete this Magento repo entry?
 
When I restore the vendor folder from a copy of the production folder I can see the output what it should have been.
 

How can I resolve this, besides just putting back a backup?