From 2f38f1e73e86da2f7e674842ea6f97db682bf4ea Mon Sep 17 00:00:00 2001
From: Nick Alexander <nalexander@mozilla.com>
Date: Wed, 26 Apr 2017 15:17:02 -0700
Subject: [PATCH] Pre: Make it easier to debug binding errors.

---
 query-projector/src/lib.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/query-projector/src/lib.rs b/query-projector/src/lib.rs
index 358667e5..64988b19 100644
--- a/query-projector/src/lib.rs
+++ b/query-projector/src/lib.rs
@@ -164,7 +164,7 @@ fn candidate_column(query: &AlgebraicQuery, var: &Variable) -> (ColumnOrExpressi
     let columns = query.cc
                        .column_bindings
                        .get(var)
-                       .expect("Every variable has a binding");
+                       .expect(format!("Every variable should have a binding, but {:?} does not", var).as_str());
 
     let qa = columns[0].clone();
     let name = VariableColumn::Variable(var.clone()).column_name();
@@ -496,4 +496,4 @@ pub fn query_projection(query: &AlgebraicQuery) -> CombinedProjection {
             },
         }
     }
-}
\ No newline at end of file
+}