[setup] fixed inconsistent version meta (#2578)

setup.py

@@ -117,14 +117,26 @@ def get_version():
 
     with open(version_txt_path) as f:
         version = f.read().strip()
-        if build_cuda_ext:
-            torch_version = '.'.join(torch.__version__.split('.')[:2])
-            cuda_version = '.'.join(get_cuda_bare_metal_version(CUDA_HOME)[1:])
-            version += f'+torch{torch_version}cu{cuda_version}'
 
     # write version into version.py
     with open(version_py_path, 'w') as f:
         f.write(f"__version__ = '{version}'\n")
+        if build_cuda_ext:
+            torch_version = '.'.join(torch.__version__.split('.')[:2])
+            cuda_version = '.'.join(get_cuda_bare_metal_version(CUDA_HOME)[1:])
+        else:
+            torch_version = None
+            cuda_version = None
+
+        if torch_version:
+            f.write(f'torch = "{torch_version}"\n')
+        else:
+            f.write('torch = None\n')
+
+        if cuda_version:
+            f.write(f'cuda = "{cuda_version}"\n')
+        else:
+            f.write('cuda = None\n')
 
     return version