Prevent model compilation on custom propagate functions (#9079)

CHANGELOG.md

@@ -30,6 +30,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 
 ### Fixed
 
+- Prevent model compilation on custom `propagate` functions ([#9079](https://github.com/pyg-team/pytorch_geometric/pull/9079))
 - Ignore `self.propagate` appearances in comments when parsing `MessagePassing` implementation ([#9044](https://github.com/pyg-team/pytorch_geometric/pull/9044))
 - Fixed `OSError` on read-only file systems within `MessagePassing` ([#9032](https://github.com/pyg-team/pytorch_geometric/pull/9032))
 - Fixed metaclass conflict in `Dataset` ([#8999](https://github.com/pyg-team/pytorch_geometric/pull/8999))

torch_geometric/nn/conv/message_passing.py

@@ -167,6 +167,10 @@ def __init__(
         # Optimize `propagate()` via `*.jinja` templates:
         if not self.propagate.__module__.startswith(jinja_prefix):
             try:
+                if 'propagate' in self.__class__.__dict__:
+                    raise ValueError("Cannot compile custom 'propagate' "
+                                     "method")
+
                 module = module_from_template(
                     module_name=f'{jinja_prefix}_propagate',
                     template_path=osp.join(root_dir, 'propagate.jinja'),
@@ -198,6 +202,10 @@ def __init__(
         if (self.inspector.implements('edge_update')
                 and not self.edge_updater.__module__.startswith(jinja_prefix)):
             try:
+                if 'edge_updater' in self.__class__.__dict__:
+                    raise ValueError("Cannot compile custom 'edge_updater' "
+                                     "method")
+
                 module = module_from_template(
                     module_name=f'{jinja_prefix}_edge_updater',
                     template_path=osp.join(root_dir, 'edge_updater.jinja'),