Workaround rust-lang#703 to prevent obscure failures due to sccache.

src/main.rs

@@ -60,6 +60,7 @@ pub mod server;
 mod test;
 
 const RUSTC_SHIM_ENV_VAR_NAME: &str = "RLS_RUSTC_SHIM";
+const RUSTC_WRAPPER_ENV_VAR: &str = "RUSTC_WRAPPER";
 
 type Span = rls_span::Span<rls_span::ZeroIndexed>;
 
@@ -73,6 +74,17 @@ pub fn main() {
 fn main_inner() -> i32 {
  env_logger::init();
 
+ // [workaround]
+ // Currently sccache breaks RLS with obscure error messages.
+ // Until it's actually fixed disable the wrapper completely
+ // in the current process tree.
+ //
+ // See https://github.com/rust-lang/rls/issues/703
+ // and https://github.com/mozilla/sccache/issues/303
+ if env::var(RUSTC_WRAPPER_ENV_VAR) != Ok("sccache".to_owned()) {
+ env::remove_var(RUSTC_WRAPPER_ENV_VAR);
+ }
+
  if env::var(RUSTC_SHIM_ENV_VAR_NAME)
  .map(|v| v != "0")
  .unwrap_or(false)