/usr/share/piuparts/htdocs/templates/ is in piuparts-master 0.77.
This file is owned by root:root, with mode 0o755.
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/usr/share/piuparts/htdocs/templates/mail/
/usr/share/piuparts/htdocs/templates/mail/broken_symlink.mail
/usr/share/piuparts/htdocs/templates/mail/copyright_file_missing_after_upgrade.mail
/usr/share/piuparts/htdocs/templates/mail/creates_system_user_in_home.mail
/usr/share/piuparts/htdocs/templates/mail/cronjob_exits_with_error_after_package_removal.mail
/usr/share/piuparts/htdocs/templates/mail/cronjob_produces_output_after_package_removal.mail
/usr/share/piuparts/htdocs/templates/mail/doesnt_use_invoke-rc.d.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_install.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_install_due_to_incorrect_dependencies_in_init.d_LSB_header.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_install_due_to_insserv_rejecting_the_script_header.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_install_purge_install.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_install_remove_distupgrade_install.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_install_remove_install.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_install_trying_to_overwrite_other_packages_files.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_purge.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_purge_-_command_deluser_adduser_in_postrm_not_found.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_purge_-_command_in_postrm_not_found.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_purge_-_command_ucf_in_postrm_not_found.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_purge_due_to_incorrect_dependencies_in_init.d_LSB_header.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_remove.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_upgrade_-_trying_to_overwrite.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_upgrade_from_jessie.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_upgrade_from_jessie_-_trying_to_overwrite.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_upgrade_from_lenny.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_upgrade_from_lenny_to_squeeze_to_wheezy.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_upgrade_from_lenny_to_squeeze_to_wheezy_-_trying_to_overwrite.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_upgrade_from_lenny_to_squeeze_to_wheezy_to_jessie.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_upgrade_from_sid_-_trying_to_overwrite.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_upgrade_from_squeeze.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_upgrade_from_squeeze_-_trying_to_overwrite.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_upgrade_from_squeeze_to_wheezy_to_jessie.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_upgrade_from_testing.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_upgrade_from_testing_-_trying_to_overwrite.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_upgrade_from_wheezy.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_upgrade_from_wheezy_-_trying_to_overwrite.mail
/usr/share/piuparts/htdocs/templates/mail/fails_to_upgrade_from_wheezy_to_jessie_to_stretch.mail
/usr/share/piuparts/htdocs/templates/mail/installs_over_existing_symlink.mail
/usr/share/piuparts/htdocs/templates/mail/leaves_alternatives_after_purge.mail
/usr/share/piuparts/htdocs/templates/mail/leaves_diversions_after_upgrade.mail
/usr/share/piuparts/htdocs/templates/mail/maintainer_script_unknown_argument.mail
/usr/share/piuparts/htdocs/templates/mail/modifies_conffiles.mail
/usr/share/piuparts/htdocs/templates/mail/modifying_files_from_another_package.mail
/usr/share/piuparts/htdocs/templates/mail/owned_after_purge_policy_6.8_+_10.7.3.mail
/usr/share/piuparts/htdocs/templates/mail/owned_and_unowned_files_after_purge_policy_6.8_+_10.7.3.mail
/usr/share/piuparts/htdocs/templates/mail/package_removed_processes_still_running.mail
/usr/share/piuparts/htdocs/templates/mail/partial-upgrade-file-overwrite.mail
/usr/share/piuparts/htdocs/templates/mail/postinst_uses_usr_share_doc.mail
/usr/share/piuparts/htdocs/templates/mail/prompting_due_to_modified_conffiles_which_were_not_modified_by_the_user.mail
/usr/share/piuparts/htdocs/templates/mail/prompts_user_without_following_Debian_Configuration_Management_Specification.mail
/usr/share/piuparts/htdocs/templates/mail/removal_makes_files_disappear.mail
/usr/share/piuparts/htdocs/templates/mail/removes_files_installed_by_other_package.mail
/usr/share/piuparts/htdocs/templates/mail/unhandled_symlink_to_directory_conversion.mail
/usr/share/piuparts/htdocs/templates/mail/uninstallable_in_sid.mail
/usr/share/piuparts/htdocs/templates/mail/unowned_directories_in_usr_local_after_purge_policy_6.8_and_9.1.2.mail
/usr/share/piuparts/htdocs/templates/mail/unowned_directory_after_purge.mail
/usr/share/piuparts/htdocs/templates/mail/unowned_files_after_purge_policy_6.8_and_10.8.mail
/usr/share/piuparts/htdocs/templates/mail/unowned_files_after_purge_policy_6.8_violating_FHS_policy_9.1_too.mail
/usr/share/piuparts/htdocs/templates/mail/unowned_files_in_usr_local_after_purge_policy_6.8.mail
/usr/share/piuparts/htdocs/templates/mail/unowned_ls-R_file_in_usr_local_after_purge.mail
/usr/share/piuparts/htdocs/templates/mail/usertag_piuparts.mail