2 files changed, 18 insertions, 4 deletions

diff --git a/crates/ra_hir/src/ty.rs b/crates/ra_hir/src/ty.rs
index f9cf3ec72..642dd02cb 100644
--- a/crates/ra_hir/src/ty.rs
+++ b/crates/ra_hir/src/ty.rs
@@ -692,3 +692,17 @@ impl HirDisplay for TraitRef {
         Ok(())
     }
 }
+
+impl HirDisplay for Obligation {
+    fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
+        match self {
+            Obligation::Trait(tr) => write!(f, "Implements({})", tr.display(f.db)),
+            Obligation::Projection(proj) => write!(
+                f,
+                "Normalize({} => {})",
+                proj.projection_ty.display(f.db),
+                proj.ty.display(f.db)
+            ),
+        }
+    }
+}
diff --git a/crates/ra_hir/src/ty/traits.rs b/crates/ra_hir/src/ty/traits.rs
index 0769e6e17..fde5d8a47 100644
--- a/crates/ra_hir/src/ty/traits.rs
+++ b/crates/ra_hir/src/ty/traits.rs
@@ -7,7 +7,7 @@ use parking_lot::Mutex;
 use ra_prof::profile;
 use rustc_hash::FxHashSet;
 
-use super::{Canonical, GenericPredicate, ProjectionTy, TraitRef, Ty};
+use super::{Canonical, GenericPredicate, HirDisplay, ProjectionTy, TraitRef, Ty};
 use crate::{db::HirDatabase, Crate, ImplBlock, Trait};
 
 use self::chalk::{from_chalk, ToChalk};
@@ -61,7 +61,6 @@ fn solve(
 ) -> Option<chalk_solve::Solution> {
     let context = ChalkContext { db, krate };
     let solver = db.trait_solver(krate);
-    debug!("solve goal: {:?}", goal);
     let solution = solver.lock().solve(&context, goal);
     debug!("solve({:?}) => {:?}", goal, solution);
     solution
@@ -120,10 +119,11 @@ pub struct ProjectionPredicate {
 pub(crate) fn trait_solve_query(
     db: &impl HirDatabase,
     krate: Crate,
-    trait_ref: Canonical<InEnvironment<Obligation>>,
+    goal: Canonical<InEnvironment<Obligation>>,
 ) -> Option<Solution> {
     let _p = profile("trait_solve_query");
-    let canonical = trait_ref.to_chalk(db).cast();
+    debug!("trait_solve_query({})", goal.value.value.display(db));
+    let canonical = goal.to_chalk(db).cast();
     // We currently don't deal with universes (I think / hope they're not yet
     // relevant for our use cases?)
     let u_canonical = chalk_ir::UCanonical { canonical, universes: 1 };