bash_version      566 src/subshell/common.c     int bash_version;
bash_version      662 src/subshell/common.c         if (sscanf (subshell_cursor_buffer, "%d:%d", &bash_version, &cursor_position) != 2)
bash_version      669 src/subshell/common.c         bash_version = 1000;
bash_version      685 src/subshell/common.c     if (bash_version < 5)  // implies SHELL_BASH