/usr/share/doc/libslepc3.7-dev/changelog.Debian.gz is in libslepc3.7-dev 3.7.4+dfsg1-2build8.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libslepc3.7-dev/../libslepc3.7.4-dev/changelog.Debian.gz