It works!

src/lib.rs

@@ -1,9 +1,14 @@
+#[macro_use]
+extern crate log;
 extern crate statrs;
 
 #[cfg(test)]
 #[macro_use]
 extern crate approx;
 
+#[cfg(test)]
+extern crate env_logger;
+
 mod factor_graph;
 mod gaussian;
 mod math;
@@ -224,7 +229,7 @@ where
     }
 
     for factor in &team_perf_layer {
-        factor.update_term(&mut variable_arena, 0);
+        factor.update_all_terms(&mut variable_arena);
     }
 
     for factor in &perf_layer {
@@ -307,6 +312,7 @@ where
 #[cfg(test)]
 mod tests {
     use approx::{AbsDiffEq, RelativeEq};
+    use env_logger;
 
     use super::*;
 
@@ -392,6 +398,8 @@ mod tests {
 
     #[test]
     fn test_rate_2vs2() {
+        let _ = env_logger::try_init();
+
         let alice = Rating::new(MU, SIGMA);
         let bob = Rating::new(MU, SIGMA);
         let chris = Rating::new(MU, SIGMA);
@@ -410,6 +418,4 @@ mod tests {
             assert_relative_eq!(rating, expected, epsilon = EPSILON);
         }
     }
-
-
 }