{"action":"opened","issue":{"url":"https://api.github.com/repos/Theano/Theano/issues/4255","repository_url":"https://api.github.com/repos/Theano/Theano","labels_url":"https://api.github.com/repos/Theano/Theano/issues/4255/labels{/name}","comments_url":"https://api.github.com/repos/Theano/Theano/issues/4255/comments","events_url":"https://api.github.com/repos/Theano/Theano/issues/4255/events","html_url":"https://github.com/Theano/Theano/issues/4255","id":141867917,"number":4255,"title":"Optimization of FGraph reports bug","user":{"login":"Sylvus","id":3027286,"avatar_url":"https://avatars.githubusercontent.com/u/3027286?v=3","gravatar_id":"","url":"https://api.github.com/users/Sylvus","html_url":"https://github.com/Sylvus","followers_url":"https://api.github.com/users/Sylvus/followers","following_url":"https://api.github.com/users/Sylvus/following{/other_user}","gists_url":"https://api.github.com/users/Sylvus/gists{/gist_id}","starred_url":"https://api.github.com/users/Sylvus/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/Sylvus/subscriptions","organizations_url":"https://api.github.com/users/Sylvus/orgs","repos_url":"https://api.github.com/users/Sylvus/repos","events_url":"https://api.github.com/users/Sylvus/events{/privacy}","received_events_url":"https://api.github.com/users/Sylvus/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2016-03-18T13:36:45Z","updated_at":"2016-03-18T13:36:45Z","closed_at":null,"body":"Hi, I'm using Lasagne and everything works fine. However, when starting my program I get the following message:\r\n\r\n> <<!! BUG IN FGRAPH.REPLACE OR A LISTENER !!>> <class 'TypeError'> ('The type of the replacement must be compatible with the type of the original Variable.', GpuAllocEmpty.0, GpuAllocEmpty.0, CudaNdarrayType(float32, (False, True, False, False)), CudaNdarrayType(float32, 4D), 'MergeOptimizer') MergeOptimizer\r\nERROR (theano.gof.opt): SeqOptimizer apply MergeOptimizer\r\nERROR (theano.gof.opt): Traceback:\r\nERROR (theano.gof.opt): Traceback (most recent call last):\r\n  File \"/usr/local/lib/python3.4/dist-packages/theano/gof/opt.py\", line 230, in apply\r\n    sub_prof = optimizer.optimize(fgraph)\r\n  File \"/usr/local/lib/python3.4/dist-packages/theano/gof/opt.py\", line 89, in optimize\r\n    ret = self.apply(fgraph, *args, **kwargs)\r\n  File \"/usr/local/lib/python3.4/dist-packages/theano/gof/opt.py\", line 817, in apply\r\n    fgraph.replace_all_validate(pairs, 'MergeOptimizer')\r\n  File \"/usr/local/lib/python3.4/dist-packages/theano/gof/toolbox.py\", line 309, in replace_all_validate\r\n    fgraph.replace(r, new_r, reason=reason, verbose=False)\r\n  File \"/usr/local/lib/python3.4/dist-packages/theano/gof/fg.py\", line 566, in replace\r\n    str(reason))\r\nTypeError: ('The type of the replacement must be compatible with the type of the original Variable.', GpuAllocEmpty.0, GpuAllocEmpty.0, CudaNdarrayType(float32, (False, True, False, False)), CudaNdarrayType(float32, 4D), 'MergeOptimizer')\r\n\r\nIt doesn't bother me because the program still runes but in case this was an unknown bug, I wanted to share it. If you want I can post my lasagne code but it is really just a collection of standard convolutional layers."}}