/usr/lib/x86_64-linux-gnu/pkgconfig/MagickCore-6.Q16.pc is in libmagickcore-6.q16-dev 8:6.9.7.4+dfsg-16ubuntu6.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/pkgconfig/ImageMagick-im6.q16.pc