/usr/lib/ is in libgflags-dev 2.2.1-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/x86_64-linux-gnu/cmake/gflags/
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/cmake/
/usr/lib/x86_64-linux-gnu/cmake/gflags/gflags-config-version.cmake
/usr/lib/x86_64-linux-gnu/cmake/gflags/gflags-config.cmake
/usr/lib/x86_64-linux-gnu/cmake/gflags/gflags-targets-release.cmake
/usr/lib/x86_64-linux-gnu/cmake/gflags/gflags-targets.cmake
/usr/lib/x86_64-linux-gnu/libgflags.a
/usr/lib/x86_64-linux-gnu/libgflags_nothreads.a
/usr/lib/x86_64-linux-gnu/pkgconfig/
/usr/lib/x86_64-linux-gnu/pkgconfig/gflags.pc
/usr/lib/x86_64-linux-gnu/libgflags.so
/usr/lib/x86_64-linux-gnu/libgflags_nothreads.so