guard against zluda and directml on non-windows platforms

Signed-off-by: Vladimir Mandic <mandic00@live.com>

CHANGELOG.md

@@ -73,6 +73,7 @@ Also, there are quite a few offloading improvements and many quality-of-life cha
   - add `--new` command line flag to enable testing of new packages without breaking existing installs  
   - downgrade rocm to `torch==2.7.1`  
   - set the minimum supported rocm version on linux to `rocm==6.0`  
+  - disallow `zluda` and `directml` on non-windows platforms  
 - **OpenVINO**
   - update to `openvino==2025.3.0`  
   - add deprecation warning for Python 3.9  

installer.py

@@ -909,6 +909,16 @@ def check_torch():
     # log.debug(f'Torch allowed: cuda={allow_cuda} rocm={allow_rocm} ipex={allow_ipex} diml={allow_directml} openvino={allow_openvino}')
     torch_command = os.environ.get('TORCH_COMMAND', '')
 
+    if sys.platform != 'win32':
+        if args.use_zluda:
+            log.error('ZLUDA is only supported on Windows')
+            if not args.ignore:
+                sys.exit(1)
+        if args.use_directml:
+            log.error('DirectML is only supported on Windows')
+            if not args.ignore:
+                sys.exit(1)
+
     if torch_command != '':
         pass
     else: