/usr/share/tripleo-image-elements/diskimage-builder/source-repository-diskimage-builder is in python-tripleo-image-elements 0.7.1-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 | diskimage-builder git /opt/stack/diskimage-builder https://git.openstack.org/openstack/diskimage-builder
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