/usr/lib/x86_64-linux-gnu/perl5/ is in libpdl-linearalgebra-perl 0.12-1build1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/x86_64-linux-gnu/perl5/5.22/
/usr/lib/x86_64-linux-gnu/perl5/5.22/PDL/
/usr/lib/x86_64-linux-gnu/perl5/5.22/PDL/LinearAlgebra/
/usr/lib/x86_64-linux-gnu/perl5/5.22/PDL/LinearAlgebra/Trans.pm
/usr/lib/x86_64-linux-gnu/perl5/5.22/PDL/LinearAlgebra/Real.pm
/usr/lib/x86_64-linux-gnu/perl5/5.22/PDL/LinearAlgebra/Complex.pm
/usr/lib/x86_64-linux-gnu/perl5/5.22/PDL/LinearAlgebra/Special.pm
/usr/lib/x86_64-linux-gnu/perl5/5.22/PDL/LinearAlgebra.pm
/usr/lib/x86_64-linux-gnu/perl5/5.22/auto/
/usr/lib/x86_64-linux-gnu/perl5/5.22/auto/PDL/
/usr/lib/x86_64-linux-gnu/perl5/5.22/auto/PDL/LinearAlgebra/
/usr/lib/x86_64-linux-gnu/perl5/5.22/auto/PDL/LinearAlgebra/Trans/
/usr/lib/x86_64-linux-gnu/perl5/5.22/auto/PDL/LinearAlgebra/Trans/Trans.so
/usr/lib/x86_64-linux-gnu/perl5/5.22/auto/PDL/LinearAlgebra/Complex/
/usr/lib/x86_64-linux-gnu/perl5/5.22/auto/PDL/LinearAlgebra/Complex/Complex.so
/usr/lib/x86_64-linux-gnu/perl5/5.22/auto/PDL/LinearAlgebra/Real/
/usr/lib/x86_64-linux-gnu/perl5/5.22/auto/PDL/LinearAlgebra/Real/Real.so