Rollup merge of #43145 - GuillaumeGomez:build-error-if-nothing, r=Mark-Simulacrum
Rollup merge of #43145 - GuillaumeGomez:build-error-if-nothing, r=Mark-Simulacrum

fail in case nothing to run was found

Fixes #43121.

r? @Mark-Simulacrum

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