After Inplace-ABN v1.0.0, a setup.py is available. However, starting from that version, the torch requirement is >=1.0. Before Inplace-ABN v1.0.0, the torch version required was >=0.4 as mentioned in the README, but Inplace-ABN did not have a setup.py.
so which version of Inplace-ABN you installed? please