https://www.jefftk.com/icdiff
https://github.com/jeffkaufman/icdiff

pip3 install git+https://github.com/jeffkaufman/icdiff.git
https://github.com/jeffkaufman/icdiff/archive/release-1.9.5.zip

build tcz using site packages installed above.
squashfs-root/usr/local/lib/python3.6/site-packages/icdiff-1.9.4-py3.6.egg-info

note: the version indicated in the site package 1.9.4 appears to be a missed update by the author, should be 1.9.5 because we installed from 1.9.5.zip

Runtime dependencies: icdiff.tcz.dep
    python3.6.tcz
    expat2.tcz
    
submitqc --color --libs --fix --strip ./icdiff.tcz

# get the extension files dates the same as tcz
for file in icdiff.tcz.*; do touch --no-create --reference=icdiff.tcz $file; done
# set the permissions
for file in icdiff.*; do chmod 666 $file; done

#tar all necessary and optional files, example:
tar cvzf ./icdiff.tar.gz ./icdiff/

save this file with name compile_icdiff