Closed issue by Anachron on void-packages repository

https://github.com/void-linux/void-packages/issues/13221

Description:
When *accidently* trying to cross-compile (for example with automation scripts) from one arch to the same it will error out with a non-descriptive error:
`XBPS_CROSS_TRIPLET is not defined`

I think it would be good to check if both `arch`s are equal and then error out displaying a msg that it's not allowed.