Don't try to use opt when cuda is not available.

theano/sandbox/cuda/blocksparse.py

@@ -182,17 +182,18 @@ sparse_block_outer_ss = SparseBlockOuterSS(False)
 sparse_block_outer_ss_inplace = SparseBlockOuterSS(True)
 
 
-@opt.register_opt()
-@opt.local_optimizer([sparse_block_gemv_ss], inplace=True)
-def local_inplace_blocksparse_gemv(node):
-    if node.op == sparse_block_gemv_ss:
-        return [sparse_block_gemv_ss_inplace(*node.inputs)]
-
-@opt.register_opt()
-@opt.local_optimizer([sparse_block_outer_ss], inplace=True)
-def local_inplace_blocksparse_outer(node):
-    if node.op == sparse_block_outer_ss:
-        return [sparse_block_outer_ss_inplace(*node.inputs)]
+if cuda_available:
+    @opt.register_opt()
+    @opt.local_optimizer([sparse_block_gemv_ss], inplace=True)
+    def local_inplace_blocksparse_gemv(node):
+        if node.op == sparse_block_gemv_ss:
+            return [sparse_block_gemv_ss_inplace(*node.inputs)]
+
+    @opt.register_opt()
+    @opt.local_optimizer([sparse_block_outer_ss], inplace=True)
+    def local_inplace_blocksparse_outer(node):
+        if node.op == sparse_block_outer_ss:
+            return [sparse_block_outer_ss_inplace(*node.inputs)]
 
 
 def sparse_block_dot_SS(W, h, inputIdx, b, outputIdx):