From f1df50809a3504e53e4c57d5d24a863385559505 Mon Sep 17 00:00:00 2001
From: Dario Coscia <dariocos99@gmail.com>
Date: Mon, 8 Sep 2025 10:52:08 +0200
Subject: [PATCH] fix compile issue

---
 .../physics_informed_solver/pinn_interface.py | 36 +++++++++++++++++++
 pina/solver/solver.py                         |  5 ++-
 2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/pina/solver/physics_informed_solver/pinn_interface.py b/pina/solver/physics_informed_solver/pinn_interface.py
index 976f6ce6b..535e7ae11 100644
--- a/pina/solver/physics_informed_solver/pinn_interface.py
+++ b/pina/solver/physics_informed_solver/pinn_interface.py
@@ -1,8 +1,10 @@
 """Module for the Physics-Informed Neural Network Interface."""
 
 from abc import ABCMeta, abstractmethod
+import warnings
 import torch
 
+from ...utils import custom_warning_format
 from ..supervised_solver import SupervisedSolverInterface
 from ...condition import (
     InputTargetCondition,
@@ -10,6 +12,10 @@
     DomainEquationCondition,
 )
 
+# set the warning for torch >= 2.8 compile
+warnings.formatwarning = custom_warning_format
+warnings.filterwarnings("always", category=UserWarning)
+
 
 class PINNInterface(SupervisedSolverInterface, metaclass=ABCMeta):
     """
@@ -46,6 +52,36 @@ def __init__(self, **kwargs):
         # current condition name
         self.__metric = None
 
+    def setup(self, stage):
+        """
+        Setup method executed at the beginning of training and testing.
+
+        This method compiles the model only if the installed torch version
+        is earlier than 2.8, due to known issues with later versions
+        (see https://github.com/mathLab/PINA/issues/621).
+
+        .. warning::
+            For torch >= 2.8, compilation is disabled. Forcing compilation
+            on these versions may cause runtime errors or unstable behavior.
+
+        :param str stage: The current stage of the training process
+            (e.g., ``fit``, ``validate``, ``test``, ``predict``).
+        :return: The result of the parent class ``setup`` method.
+        :rtype: Any
+        """
+        # Override the compilation, compiling only for torch < 2.8, see
+        # related issue at https://github.com/mathLab/PINA/issues/621
+        if torch.__version__ < "2.8":
+            self.trainer.compile = True
+        else:
+            self.trainer.compile = False
+            warnings.warn(
+                "Compilation is disabled for torch >= 2.8. "
+                "Forcing compilation may cause runtime errors or instability.",
+                UserWarning,
+            )
+        return super().setup(stage)
+
     def optimization_cycle(self, batch, loss_residuals=None):
         """
         The optimization cycle for the PINN solver.
diff --git a/pina/solver/solver.py b/pina/solver/solver.py
index f6bcc2ac2..f3ff40579 100644
--- a/pina/solver/solver.py
+++ b/pina/solver/solver.py
@@ -169,7 +169,10 @@ def setup(self, stage):
         compile the model if the :class:`~pina.trainer.Trainer`
         ``compile`` is ``True``.
 
-
+        :param str stage: The current stage of the training process
+            (e.g., ``fit``, ``validate``, ``test``, ``predict``).
+        :return: The result of the parent class ``setup`` method.
+        :rtype: Any
         """
         if stage == "fit" and self.trainer.compile:
             self._setup_compile()