Fix: Bad compatibility with InstructionProperties

- Make `InstructionProperties` "_calibration" attribute visible.
- Removed attribute "calibration", treat as class property.
- Other tweaks and fixes

crates/accelerate/src/target.rs

@@ -63,7 +63,8 @@ pub struct InstructionProperties {
     pub duration: Option<f32>,
     #[pyo3(get, set)]
     pub error: Option<f32>,
-    pub calibration: Option<PyObject>,
+    #[pyo3(get)]
+    _calibration: Option<PyObject>,
 }
 
 #[pymethods]
@@ -74,33 +75,31 @@ impl InstructionProperties {
         calibration: Schedule | ScheduleBlock | CalibrationEntry | None = None,)")]
     pub fn new(duration: Option<f32>, error: Option<f32>, calibration: Option<PyObject>) -> Self {
         InstructionProperties {
-            calibration,
             error,
             duration,
+            _calibration: calibration,
         }
     }
 
     #[getter]
     pub fn get_calibration(&self, py: Python<'_>) -> Option<PyObject> {
-        match &self.calibration {
+        match &self._calibration {
             Some(calibration) => calibration.call_method0(py, "get_schedule").ok(),
             None => None,
         }
     }
 
     #[setter]
     pub fn set_calibration(&mut self, py: Python<'_>, calibration: Bound<PyAny>) -> PyResult<()> {
-        self.calibration = Some(calibration.to_object(py));
+        self._calibration = Some(calibration.to_object(py));
         Ok(())
     }
 
     fn __repr__(&self, py: Python<'_>) -> String {
         if let Some(calibration) = self.get_calibration(py) {
             format!(
                 "InstructionProperties(duration={:?}, error={:?}, calibration={:?})",
-                self.duration,
-                self.error,
-                calibration.call_method0(py, "__repr__")
+                self.duration, self.error, calibration
             )
         } else {
             format!(

qiskit/transpiler/_target.py

@@ -91,6 +91,10 @@ def duration(self):
     def error(self):
         return self._InsrProp.error
 
+    @property
+    def _calibration(self):
+        return self._InsrProp._calibration
+
     @error.setter
     def error(self, other):
         self._InsrProp.error = other
@@ -332,7 +336,7 @@ def update_from_instruction_schedule_map(self, inst_map, inst_name_map=None, err
                     props = None
 
                 entry = get_calibration(inst_name, qargs)
-                if entry.user_provided and getattr(props, "calibration", None) != entry:
+                if entry.user_provided and getattr(props, "_calibration", None) != entry:
                     # It only copies user-provided calibration from the inst map.
                     # Backend defined entry must already exist in Target.
                     if self.dt is not None:
@@ -380,7 +384,7 @@ def update_from_instruction_schedule_map(self, inst_map, inst_name_map=None, err
                         if isinstance(qargs, int):
                             qargs = (qargs,)
                         qlen.add(len(qargs))
-                        cal = getattr(out_props[tuple(qargs)], "calibration")
+                        cal = getattr(out_props[tuple(qargs)], "_calibration")
                         param_names.add(tuple(cal.get_signature().parameters.keys()))
                     if len(qlen) > 1 or len(param_names) > 1:
                         raise QiskitError(