Ubuntu 20.04 Whitaker Words ./words does not work : solution

После переезда 18.04 -> 20.04 отвалились Whitaker Words. Диагностика:

Step 1.

$ ./words
./words: error while loading shared libraries: libgcc_s.so.1: wrong ELF class: ELFCLASS64

Step 2.

$ readelf -d ./words

Dynamic section at offset 0xa95a0 contains 21 entries:
  Tag        Type                         Name/Value
 0x00000001 (NEEDED)                     Shared library: [libgcc_s.so.1]
 0x00000001 (NEEDED)                     Shared library: [libc.so.6]
 0x0000000c (INIT)                       0x8049530
 0x0000000d (FINI)                       0x80cd710
 0x00000004 (HASH)                       0x8048168
 0x00000005 (STRTAB)                     0x8048ba0
 0x00000006 (SYMTAB)                     0x80484b0
 0x0000000a (STRSZ)                      1282 (bytes)
 0x0000000b (SYMENT)                     16 (bytes)
 0x00000015 (DEBUG)                      0x0
 0x00000003 (PLTGOT)                     0x80f26d8
 0x00000002 (PLTRELSZ)                   656 (bytes)
 0x00000014 (PLTREL)                     REL
 0x00000017 (JMPREL)                     0x80492a0
 0x00000011 (REL)                        0x80491d0
 0x00000012 (RELSZ)                      208 (bytes)
 0x00000013 (RELENT)                     8 (bytes)
 0x6ffffffe (VERNEED)                    0x8049180
 0x6fffffff (VERNEEDNUM)                 2
 0x6ffffff0 (VERSYM)                     0x80490a2
 0x00000000 (NULL)                       0x0

Step 3.

$ sudo apt install libc.so.6
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package libc.so.6

$ sudo apt install libgcc_s.so.1
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package libgcc_s.so.1

Step 4.

$ sudo apt-get install gcc-multilib

После этого работает нормально.