/usr/lib/x86_64-linux-gnu/ is in libkf5imap-dev 15.12.3-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/x86_64-linux-gnu/qt5/mkspecs/modules/
/usr/lib/x86_64-linux-gnu/cmake/
/usr/lib/x86_64-linux-gnu/cmake/KF5IMAP/
/usr/lib/x86_64-linux-gnu/cmake/KF5IMAP/KF5IMAPConfigVersion.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5IMAP/KF5IMAPTargets-debian.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5IMAP/KF5IMAPTargets.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5IMAP/KF5IMAPConfig.cmake
/usr/lib/x86_64-linux-gnu/cmake/KF5IMAP/FindSasl2.cmake
/usr/lib/x86_64-linux-gnu/qt5/
/usr/lib/x86_64-linux-gnu/qt5/mkspecs/
/usr/lib/x86_64-linux-gnu/qt5/mkspecs/modules/qt_KIMAP.pri
/usr/lib/x86_64-linux-gnu/libkimaptest.a
/usr/lib/x86_64-linux-gnu/libKF5IMAP.so