libspatialindex-dev 1.9.3-1build1 (armhf binary) in ubuntu focal

 Spatialindex is a C++ library that provides a framework for
 developing spatial indices. Currently it defines generic interfaces,
 provides simple main memory and disk based storage managers and a
 robust implementation of an R*-tree, an MVR-tree and a TPR-tree.
 .
 This package contains the development files to build third
 parties programs.