clippy: Fix option_env_unwrap

rr_frontend/.cargo/config.toml

@@ -27,7 +27,6 @@ rustflags = [
     "-Aclippy::useless_format",
 
     # clippy::correctness
-    "-Aclippy::option_env_unwrap",
     "-Aclippy::redundant_locals",
     "-Aclippy::unused_io_amount",
 

rr_frontend/analysis/tests/utils.rs

@@ -19,6 +19,7 @@ pub fn find_compiled_executable(name: &str) -> PathBuf {
     );
 }
 
+#[allow(clippy::option_env_unwrap)]
 pub fn find_sysroot() -> String {
     // Taken from https://github.com/Manishearth/rust-clippy/pull/911.
     let home = option_env!("RUSTUP_HOME").or(option_env!("MULTIRUST_HOME"));