/usr/share/doc/libmuscle-3.7-dev/changelog.Debian.gz is in libmuscle-3.7-dev 3.7+4565-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/libmuscle-3.7-dev/../libmuscle-3.7-1/changelog.Debian.gz