Install cpp-i686-linux-gnu by entering the following commands in the terminal:
sudo apt update sudo apt install cpp-i686-linux-gnu
GNU C preprocessor (cpp) for the i386 architecture
The GNU C preprocessor is a macro processor that is used automatically by the GNU C compiler to transform programs before actual compilation. . This package has been separated from gcc for the benefit of those who require the preprocessor but not the cross-compiler for i386 architecture. . This is a dependency package providing the default GNU C preprocessor for the i386 architecture.