Add env variable to disable macOS MPS devices, closes #592

.github/workflows/build.yml

@@ -40,6 +40,7 @@ jobs:
       - name: Install dependencies - macOS
         run: |
           echo "OMP_NUM_THREADS=1" >> $GITHUB_ENV
+          echo "PYTORCH_MPS_DISABLE=1" >> $GITHUB_ENV
         if: matrix.os == 'macos-latest'
 
       - name: Install dependencies - Windows

src/python/txtai/models/models.py

@@ -132,7 +132,7 @@ def reference(deviceid):
             else f"cuda:{deviceid}"
             if torch.cuda.is_available()
             else "mps"
-            if torch.backends.mps.is_available()
+            if Models.hasmpsdevice()
             else Models.finddevice()
         )
 
@@ -145,7 +145,18 @@ def hasaccelerator():
             True if an accelerator device is available, False otherwise
         """
 
-        return torch.cuda.is_available() or torch.backends.mps.is_available() or bool(Models.finddevice())
+        return torch.cuda.is_available() or Models.hasmpsdevice() or bool(Models.finddevice())
+
+    @staticmethod
+    def hasmpsdevice():
+        """
+        Checks if there is a MPS device available.
+
+        Returns:
+            True if a MPS device is available, False otherwise
+        """
+
+        return os.environ.get("PYTORCH_MPS_DISABLE") != "1" and torch.backends.mps.is_available()
 
     @staticmethod
     def finddevice():