Improve invalid namespace error msg

r1cs-std/src/test_constraint_system.rs

@@ -132,7 +132,7 @@ impl TestConstraintSystem {
 
 fn compute_path(ns: &[String], this: String) -> String {
     if this.chars().any(|a| a == '/') {
-        panic!("'/' is not allowed in names");
+        panic!(format!("'/' is not allowed in namespace names. Error in namespace name: {:?}", this));
     }
 
     let mut name = String::new();