3 files changed, 6 insertions, 3 deletions
diff --git a/compiler/rustc_span/src/hygiene.rs b/compiler/rustc_span/src/hygiene.rs
index aa4bcefab93..00ef17d630c 100644
--- a/compiler/rustc_span/src/hygiene.rs
+++ b/compiler/rustc_span/src/hygiene.rs
@@ -40,6 +40,7 @@ use std::cell::RefCell;
 use std::collections::hash_map::Entry;
 use std::fmt;
 use std::hash::Hash;
+use tracing::{debug, trace};
 
 /// A `SyntaxContext` represents a chain of pairs `(ExpnId, Transparency)` named "marks".
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
diff --git a/compiler/rustc_span/src/lib.rs b/compiler/rustc_span/src/lib.rs
index f83bacdcebe..b2ca01fe3b9 100644
--- a/compiler/rustc_span/src/lib.rs
+++ b/compiler/rustc_span/src/lib.rs
@@ -33,15 +33,16 @@
 #![feature(rustdoc_internals)]
 // tidy-alphabetical-end
 
+// The code produced by the `Encodable`/`Decodable` derive macros refer to
+// `rustc_span::Span{Encoder,Decoder}`. That's fine outside this crate, but doesn't work inside
+// this crate without this line making `rustc_span` available.
 extern crate self as rustc_span;
 
-#[macro_use]
-extern crate tracing;
-
 use rustc_data_structures::{outline, AtomicRef};
 use rustc_macros::{Decodable, Encodable, HashStable_Generic};
 use rustc_serialize::opaque::{FileEncoder, MemDecoder};
 use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};
+use tracing::debug;
 
 mod caching_source_map_view;
 pub mod source_map;
diff --git a/compiler/rustc_span/src/source_map.rs b/compiler/rustc_span/src/source_map.rs
index 2093dcf0e83..fb212d67997 100644
--- a/compiler/rustc_span/src/source_map.rs
+++ b/compiler/rustc_span/src/source_map.rs
@@ -16,6 +16,7 @@ use rustc_macros::{Decodable, Encodable};
 use std::fs;
 use std::io::{self, BorrowedBuf, Read};
 use std::path;
+use tracing::{debug, instrument, trace};
 
 #[cfg(test)]
 mod tests;