Define the unavailable target just once and re-use it
Define the unavailable target just once and re-use it

The same unavailable target value is used in two different places.
Abstracting it makes it easier to update it and recognise its purpose.

GBGamer/rust,aidancully/rust,aidancully/rust,GBGamer/rust,GBGamer/rust,graydon/rust,aidancully/rust,GBGamer/rust,graydon/rust,aidancully/rust,graydon/rust,graydon/rust,GBGamer/rust,GBGamer/rust,graydon/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,graydon/rust,aidancully/rust