Got pointed to it by a student at pbs@dartmouth -- boils down to still remaining delayed import of deprecated (removed in python 3) `cmp`: ```shell ❯ git describe --tags 1.8.6-118-g42302ed75 ❯ git grep -p 'import cmp' nipype/interfaces/cmtk/parcellation.py=def create_annot_label(subject_id, subjects_dir, fs_dir, parcellation_name): nipype/interfaces/cmtk/parcellation.py: import cmp nipype/interfaces/cmtk/parcellation.py=def create_roi(subject_id, subjects_dir, fs_dir, parcellation_name, dilation): nipype/interfaces/cmtk/parcellation.py: import cmp nipype/interfaces/cmtk/parcellation.py=def create_wm_mask(subject_id, subjects_dir, fs_dir, parcellation_name): nipype/interfaces/cmtk/parcellation.py: import cmp ```