/usr/lib/petscdir/3.4.2/makefile.html is in petsc3.4.2-doc 3.4.2.dfsg1-6.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/petscdir/3.4.2/../../../share/doc/petsc3.4.2-doc/makefile.html
/usr/lib/petscdir/3.4.2/../../../share/doc/petsc3.4.2-doc/makefile.html