[Cache] raise errors for `tileang.clear_cache()` (#1077)

tilelang/cache/__init__.py

@@ -39,9 +39,15 @@ def cached(
 
 def clear_cache():
     """
-    Clears the entire kernel cache (using KernelCache class).
+    Disabled helper that previously removed the entire kernel cache.
+
+    Raises:
+        RuntimeError: Always raised to warn users to clear the cache manually.
     """
-    _kernel_cache_instance.clear_cache()
+    cache_dir = env.TILELANG_CACHE_DIR
+    raise RuntimeError("tilelang.clear_cache() is disabled because deleting the cache directory "
+                       "is dangerous. If you accept the risk, remove it manually with "
+                       f"`rm -rf '{cache_dir}'`.")
 
 
 if env.TILELANG_CLEAR_CACHE.lower() in ("1", "true", "yes", "on"):