/usr/lib/python2.7/dist-packages/trytond/modules/ is in tryton-modules-account-dunning-letter 3.4.0-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/__init__.py
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/dunning.py
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/dunning.xml
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/letter.odt
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/locale/
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/locale/ca_ES.po
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/locale/de_DE.po
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/locale/es_AR.po
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/locale/es_CO.po
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/locale/es_EC.po
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/locale/es_ES.po
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/locale/fr_FR.po
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/locale/sl_SI.po
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/tests/
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/tests/__init__.py
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/tests/test_account_dunning_letter.py
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/tryton.cfg
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/view/
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/view/dunning_level_form.xml
/usr/lib/python2.7/dist-packages/trytond/modules/account_dunning_letter/view/dunning_level_list.xml