Have tried following the dependency for: libmotif-dev → libxft-dev → libfontconfig1-dev → libfreetype6-dev → libpng-dev
where finally resolved by 'apt install libpng-dev' which removed an older installed packge, libpng16-dev and replaced with newer libpng12-dev
M. de Marneffe, C. Manning, and C. Potts. Proceedings of the 48th Annual Meeting of the Association for Computational Linguistics, page 167--176. Stroudsburg, PA, USA, Association for Computational Linguistics, (2010)
F. Güler, and A. Birturk. Proceedings of the 18th International Conference on Conceptual Structures (ICCS 2010), volume 6208 of Lecture Notes in Computer Science, page 97-107. Springer, (2010)