Add tests for rustc context build script env vars
Add tests for rustc context build script env vars

rustyhorde/cargo,rustyhorde/cargo,rust-lang/cargo,eminence/cargo,eminence/cargo,rust-lang/cargo,nipunn1313/cargo,nipunn1313/cargo,nipunn1313/cargo,eminence/cargo,rustyhorde/cargo,eminence/cargo,rust-lang/cargo,rust-lang/cargo,nipunn1313/cargo,rustyhorde/cargo