fix inconsistent check between kinematic and kinematic_coverage

validphys2/src/validphys/commondataparser.py

@@ -433,9 +433,9 @@ class ObservableMetaData:
 
         # Ensure that all variables in the kinematic coverage exist
         for var in self.kinematic_coverage:
-            if var not in self.kinematics.variables:
+            if var not in self.kinematics.variables and not var.startswith("extra_"):
                 raise ValidationError(
-                    f"Variable {var} is in `kinematic_coverage` but not included in `kinematics` for {self.name}"
+                    f"Variable {var} is in `kinematic_coverage` but not included in `kinematics` nor part as `extra_` for {self.name}"
                 )
 
         if len(self.kinematic_coverage) > 3:

validphys2/src/validphys/process_options.py

@@ -85,6 +85,7 @@ class _Process:
         if kin_cov == ["k1", "k2", "k3"]:
             return True
         # We check if kin_cov is a subset of self.accepted_variables
+        kin_cov = [v for v in kin_cov if not v.startswith("extra_")]
         return set(self.accepted_variables).union(set(kin_cov)) == set(self.accepted_variables)
 
     def xq2map(self, kin_df, metadata):