/usr/share/idl/GNOME_Gnumeric.idl is in gnumeric 1.10.17-1.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/idl/../gnumeric/1.10.17/idl/GNOME_Gnumeric.idl
/usr/share/idl/../gnumeric/1.10.17/idl/GNOME_Gnumeric.idl