Throw NotSupported instead of InvalidInstance

.gitignore

@@ -157,3 +157,10 @@ fabric.properties
 
 # Android studio 3.1+ serialized cache file
 .idea/caches/build_file_checksums.ser
+
+# IDEA config files - idk if we actually need these?
+.idea/vcs.xml
+.idea/misc.xml
+.idea/inspectionProfiles
+.idea/.gitignore
+.idea/conjure-oxide.iml

conjure_oxide/src/solvers/kissat.rs

@@ -235,10 +235,8 @@ impl FromConjureModel for CNF {
  match ans.add_expression(&expr) {
  Ok(_) => {}
  Err(error) => {
- let message = format!("Error converting to CNF: {:?}", error);
- // Nik has said that InvalidInstance should be thrown for cases where the model cannot be converted
- // So, we use the actual CNF error as the message and throw a SolverError from it
- return Err(SolverError::InvalidInstance(SOLVER, message));
+ let message = format!("{:?}", error);
+ return Err(SolverError::NotSupported(SOLVER, message));
  }
  }
  }