/usr/ is in libpurify-dev 2.0.0-2.
This file is owned by root:root, with mode 0o755.
..
/usr/include/
/usr/include/purify/
/usr/include/purify/FFTOperator.h
/usr/include/purify/MeasurementOperator.h
/usr/include/purify/PSFOperator.h
/usr/include/purify/RMOperator.h
/usr/include/purify/casacore.h
/usr/include/purify/clean.h
/usr/include/purify/config.h
/usr/include/purify/kernels.h
/usr/include/purify/logging.disabled.h
/usr/include/purify/logging.enabled.h
/usr/include/purify/logging.h
/usr/include/purify/pfitsio.h
/usr/include/purify/types.h
/usr/include/purify/utilities.h
/usr/lib/
/usr/lib/x86_64-linux-gnu/
/usr/share/
/usr/share/cmake/
/usr/share/cmake/purify/
/usr/share/cmake/purify/PurifyConfig.cmake
/usr/share/cmake/purify/PurifyConfigVersion.cmake
/usr/share/cmake/purify/PurifyTargets-none.cmake
/usr/share/cmake/purify/PurifyTargets.cmake
/usr/share/doc/
/usr/share/doc/libpurify-dev/
/usr/share/doc/libpurify-dev/copyright
/usr/lib/x86_64-linux-gnu/libpurify.so
/usr/share/doc/libpurify-dev/changelog.Debian.gz