/usr/lib/x86_64-linux-gnu/ is in libhdf5-mpich-dev 1.8.16+docs-4ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/x86_64-linux-gnu/libhdf5_mpich.a
/usr/lib/x86_64-linux-gnu/pkgconfig/
/usr/lib/x86_64-linux-gnu/pkgconfig/hdf5-mpich.pc
/usr/lib/x86_64-linux-gnu/libhdf5_mpich_fortran.a
/usr/lib/x86_64-linux-gnu/libhdf5_mpich.settings
/usr/lib/x86_64-linux-gnu/libhdf5_mpichhl_fortran.a
/usr/lib/x86_64-linux-gnu/libhdf5_mpich_hl.a
/usr/lib/x86_64-linux-gnu/hdf5/
/usr/lib/x86_64-linux-gnu/hdf5/mpich/
/usr/lib/x86_64-linux-gnu/libhdf5_mpich.so
/usr/lib/x86_64-linux-gnu/libhdf5_mpich_fortran.so
/usr/lib/x86_64-linux-gnu/libhdf5_mpichhl_fortran.so
/usr/lib/x86_64-linux-gnu/libhdf5_mpich_hl.so
/usr/lib/x86_64-linux-gnu/hdf5/mpich/libhdf5hl_fortran.a
/usr/lib/x86_64-linux-gnu/hdf5/mpich/libhdf5_hl.a
/usr/lib/x86_64-linux-gnu/hdf5/mpich/libhdf5.a
/usr/lib/x86_64-linux-gnu/hdf5/mpich/lib
/usr/lib/x86_64-linux-gnu/hdf5/mpich/libhdf5_fortran.so
/usr/lib/x86_64-linux-gnu/hdf5/mpich/libhdf5.so
/usr/lib/x86_64-linux-gnu/hdf5/mpich/include
/usr/lib/x86_64-linux-gnu/hdf5/mpich/libhdf5.settings
/usr/lib/x86_64-linux-gnu/hdf5/mpich/libhdf5hl_fortran.so
/usr/lib/x86_64-linux-gnu/hdf5/mpich/libhdf5_fortran.a
/usr/lib/x86_64-linux-gnu/hdf5/mpich/libhdf5_hl.so