Don't use failure as a compat layer for JSON-RPC errors

Author: Xanewok

Cargo.lock

@@ -14,7 +14,6 @@ log = "0.4"
 rand = "0.7"
 clippy_lints = { git = "https://github.com/rust-lang/rust-clippy", rev = "d236b30a1d638340aad8345fa2946cfe9543dcf0", optional = true }
 tokio = { version = "0.1", optional = true }
-failure = { version = "0.1" }
 futures = { version = "0.1", optional = true }
 serde = { version = "1", features = ["derive"], optional = true }
 rls-data = { version = "0.19", optional = true }

rls-rustc/Cargo.toml

@@ -2,7 +2,6 @@ use std::collections::{HashMap, HashSet};
 use std::io;
 use std::path::{Path, PathBuf};
 
-use failure::Fail;
 use futures::Future;
 
 use rls_ipc::client::{Client as JointClient, RpcChannel, RpcError};
@@ -38,7 +37,7 @@ impl rustc_span::source_map::FileLoader for IpcFileLoader {
         self.0
             .read_file(path.to_owned())
             .wait()
-            .map_err(|e| io::Error::new(io::ErrorKind::Other, e.compat()))
+            .map_err(|e| io::Error::new(io::ErrorKind::Other, format!("{}", e)))
     }
 }