From 0ed0e78cc510d0d0f463e133700e8ea32af9d8eb Mon Sep 17 00:00:00 2001
From: usmanmateen <74776275+usmanmateen@users.noreply.github.com>
Date: Wed, 21 Oct 2026 09:23:58 +0100
Subject: [PATCH 1/3] Add a test for importing models with torchao older than
 0.15

---
 tests/others/test_dependencies.py | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/tests/others/test_dependencies.py b/tests/others/test_dependencies.py
index 924f5418cc40..d7382303357e 100644
--- a/tests/others/test_dependencies.py
+++ b/tests/others/test_dependencies.py
@@ -13,6 +13,9 @@
 # limitations under the License.
 
 import inspect
+import os
+import subprocess
+import sys
 from importlib import import_module
 
 import pytest
@@ -22,6 +25,25 @@ class TestDependencies:
     def test_diffusers_import(self):
         import diffusers  # noqa: F401
 
+    def test_model_import_with_torchao_older_than_0_15(self, tmp_path):
+        # FqnToConfig only exists from torchao 0.15. An older torchao, such as the one on Google Colab, must not
+        # stop models from importing.
+        (tmp_path / "torchao" / "quantization").mkdir(parents=True)
+        (tmp_path / "torchao" / "__init__.py").write_text("")
+        (tmp_path / "torchao" / "quantization" / "__init__.py").write_text(
+            "def quantize_(*args, **kwargs):\n    pass\n"
+        )
+        (tmp_path / "torchao-0.14.1.dist-info").mkdir()
+        (tmp_path / "torchao-0.14.1.dist-info" / "METADATA").write_text(
+            "Metadata-Version: 2.1\nName: torchao\nVersion: 0.14.1\n"
+        )
+        env = {**os.environ, "PYTHONPATH": os.pathsep.join([str(tmp_path), os.environ.get("PYTHONPATH", "")])}
+
+        result = subprocess.run(
+            [sys.executable, "-c", "from diffusers import UNet2DModel"], env=env, capture_output=True, text=True
+        )
+        assert result.returncode == 0, result.stderr
+
     def test_backend_registration(self):
         import diffusers
         from diffusers.dependency_versions_table import deps

From 1f66033eb3c4577a5fd64c6ff6f946b543383de0 Mon Sep 17 00:00:00 2001
From: usmanmateen <74776275+usmanmateen@users.noreply.github.com>
Date: Wed, 21 Oct 2026 09:23:58 +0100
Subject: [PATCH 2/3] Only import FqnToConfig from torchao 0.15 on

torchao_quantizer.py imported FqnToConfig whenever torchao was installed,
but it only exists from torchao 0.15. With an older torchao, importing any
model failed, including on Google Colab.
---
 src/diffusers/quantizers/torchao/torchao_quantizer.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/diffusers/quantizers/torchao/torchao_quantizer.py b/src/diffusers/quantizers/torchao/torchao_quantizer.py
index 8e781ebb143a..e31db9faa068 100644
--- a/src/diffusers/quantizers/torchao/torchao_quantizer.py
+++ b/src/diffusers/quantizers/torchao/torchao_quantizer.py
@@ -51,7 +51,8 @@
     import torch
     import torch.nn as nn
 
-if is_torchao_available():
+# `validate_environment` asks for torchao >= 0.15 before quantizing, and older versions have no `FqnToConfig`.
+if is_torchao_available() and is_torchao_version(">=", "0.15.0"):
     from torchao.quantization import FqnToConfig, quantize_
 
     if is_torchao_version(">=", "0.16.0"):

From 6ed7a1ec28bb80fd28f9d4c59813465a1716b15d Mon Sep 17 00:00:00 2001
From: usmanmateen <74776275+usmanmateen@users.noreply.github.com>
Date: Wed, 21 Oct 2026 09:33:06 +0100
Subject: [PATCH 3/3] Remove the torchao import test

---
 tests/others/test_dependencies.py | 22 ----------------------
 1 file changed, 22 deletions(-)

diff --git a/tests/others/test_dependencies.py b/tests/others/test_dependencies.py
index d7382303357e..924f5418cc40 100644
--- a/tests/others/test_dependencies.py
+++ b/tests/others/test_dependencies.py
@@ -13,9 +13,6 @@
 # limitations under the License.
 
 import inspect
-import os
-import subprocess
-import sys
 from importlib import import_module
 
 import pytest
@@ -25,25 +22,6 @@ class TestDependencies:
     def test_diffusers_import(self):
         import diffusers  # noqa: F401
 
-    def test_model_import_with_torchao_older_than_0_15(self, tmp_path):
-        # FqnToConfig only exists from torchao 0.15. An older torchao, such as the one on Google Colab, must not
-        # stop models from importing.
-        (tmp_path / "torchao" / "quantization").mkdir(parents=True)
-        (tmp_path / "torchao" / "__init__.py").write_text("")
-        (tmp_path / "torchao" / "quantization" / "__init__.py").write_text(
-            "def quantize_(*args, **kwargs):\n    pass\n"
-        )
-        (tmp_path / "torchao-0.14.1.dist-info").mkdir()
-        (tmp_path / "torchao-0.14.1.dist-info" / "METADATA").write_text(
-            "Metadata-Version: 2.1\nName: torchao\nVersion: 0.14.1\n"
-        )
-        env = {**os.environ, "PYTHONPATH": os.pathsep.join([str(tmp_path), os.environ.get("PYTHONPATH", "")])}
-
-        result = subprocess.run(
-            [sys.executable, "-c", "from diffusers import UNet2DModel"], env=env, capture_output=True, text=True
-        )
-        assert result.returncode == 0, result.stderr
-
     def test_backend_registration(self):
         import diffusers
         from diffusers.dependency_versions_table import deps