Install libptexenc-dev by entering the following commands in the terminal:
sudo apt update sudo apt install libptexenc-dev
Description:
TeX Live: ptex encoding library (development part)
This package contains the static library and header files for the ptexenc library, a library for encoding support in pTeX, a Japanese TeX engine.
Homepage: http://www.tug.org/texlive/
Version: 2017.20170613.44572-8build1
Section: libdevel