Step-by-step – GCC 10.3 Installation in Debian Bullseye

Installing Requirements

5. 5. Installing Dependencies

   Now to Install Required Dependencies
   Now install the Dependency Package with Multilib support with:

   sudo apt install build-essential libncurses-dev bison flex libssl-dev libelf-dev gcc-multilib

   Then access the Target Directory:

   cd ~/Downloads/gcc-10.*/

   And again to Download the Required Libraries play:

   ./contrib/download_prerequisites