./build.sh gcc-djgpp ends with [Makefile:487: memcpy-chk.lo] Error 1

Trail of the output:

make[6]: Entering directory '/home/[...]/proj/build-ia16.202501/build-djgpp/ia16-elf/elkslibc/libssp'
/bin/bash ./libtool --tag=CC   --mode=compile ia16-elf-gcc  -mr=elks -DHAVE_CONFIG_H -I. -I../../../../gcc-ia16/libssp    -Wall -g -O2  -mr=elks -MT ssp.lo -MD -MP -MF .deps/ssp.Tpo -c -o ssp.lo ../../../../gcc-ia16/libssp/ssp.c
/bin/bash ./libtool --tag=CC   --mode=compile ia16-elf-gcc  -mr=elks -DHAVE_CONFIG_H -I. -I../../../../gcc-ia16/libssp    -Wall -g -O2  -mr=elks -MT gets-chk.lo -MD -MP -MF .deps/gets-chk.Tpo -c -o gets-chk.lo ../../../../gcc-ia16/libssp/gets-chk.c
/bin/bash ./libtool --tag=CC   --mode=compile ia16-elf-gcc  -mr=elks -DHAVE_CONFIG_H -I. -I../../../../gcc-ia16/libssp    -Wall -g -O2  -mr=elks -MT memcpy-chk.lo -MD -MP -MF .deps/memcpy-chk.Tpo -c -o memcpy-chk.lo ../../../../gcc-ia16/libssp/memcpy-chk.c
/bin/bash ./libtool --tag=CC   --mode=compile ia16-elf-gcc  -mr=elks -DHAVE_CONFIG_H -I. -I../../../../gcc-ia16/libssp    -Wall -g -O2  -mr=elks -MT memmove-chk.lo -MD -MP -MF .deps/memmove-chk.Tpo -c -o memmove-chk.lo ../../../../gcc-ia16/libssp/memmove-chk.c
libtool: compile:  ia16-elf-gcc -mr=elks -DHAVE_CONFIG_H -I. -I../../../../gcc-ia16/libssp -Wall -g -O2 -mr=elks -MT ssp.lo -MD -MP -MF .deps/ssp.Tpo -c ../../../../gcc-ia16/libssp/ssp.c -o ssp.o
libtool: compile:  ia16-elf-gcc -mr=elks -DHAVE_CONFIG_H -I. -I../../../../gcc-ia16/libssp -Wall -g -O2 -mr=elks -MT memcpy-chk.lo -MD -MP -MF .deps/memcpy-chk.Tpo -c ../../../../gcc-ia16/libssp/memcpy-chk.c -o memcpy-chk.o
libtool: compile:  ia16-elf-gcc -mr=elks -DHAVE_CONFIG_H -I. -I../../../../gcc-ia16/libssp -Wall -g -O2 -mr=elks -MT gets-chk.lo -MD -MP -MF .deps/gets-chk.Tpo -c ../../../../gcc-ia16/libssp/gets-chk.c -o gets-chk.o
libtool: compile:  ia16-elf-gcc -mr=elks -DHAVE_CONFIG_H -I. -I../../../../gcc-ia16/libssp -Wall -g -O2 -mr=elks -MT memmove-chk.lo -MD -MP -MF .deps/memmove-chk.Tpo -c ../../../../gcc-ia16/libssp/memmove-chk.c -o memmove-chk.o
cc1: warning: target system does not support debug output
cc1: warning: target system does not support debug output
cc1: warning: target system does not support debug output
../../../../gcc-ia16/libssp/ssp.c: In function ‘__guard_setup’:
../../../../gcc-ia16/libssp/ssp.c:137:8: warning: implicit declaration of function ‘open’ [-Wimplicit-function-declaration]
   fd = open ("/dev/urandom", O_RDONLY);
        ^~~~
../../../../gcc-ia16/libssp/ssp.c:137:30: error: ‘O_RDONLY’ undeclared (first use in this function)
   fd = open ("/dev/urandom", O_RDONLY);
                              ^~~~~~~~
../../../../gcc-ia16/libssp/ssp.c:137:30: note: each undeclared identifier is reported only once for each function it appears in
../../../../gcc-ia16/libssp/ssp.c:140:7: error: unknown type name ‘ssize_t’
       ssize_t size = read (fd, &__stack_chk_guard,
       ^~~~~~~
../../../../gcc-ia16/libssp/ssp.c:140:22: warning: implicit declaration of function ‘read’ [-Wimplicit-function-declaration]
       ssize_t size = read (fd, &__stack_chk_guard,
                      ^~~~
../../../../gcc-ia16/libssp/ssp.c:142:7: warning: implicit declaration of function ‘close’ [-Wimplicit-function-declaration]
       close (fd);
       ^~~~~
../../../../gcc-ia16/libssp/ssp.c: At top level:
../../../../gcc-ia16/libssp/ssp.c:157:25: error: unknown type name ‘size_t’
 fail (const char *msg1, size_t msg1len, const char *msg3)
                         ^~~~~~
../../../../gcc-ia16/libssp/ssp.c: In function ‘__stack_chk_fail’:
../../../../gcc-ia16/libssp/ssp.c:229:3: warning: implicit declaration of function ‘fail’ [-Wimplicit-function-declaration]
   fail (msg, strlen (msg), "stack smashing detected: terminated");
   ^~~~
../../../../gcc-ia16/libssp/ssp.c:229:14: warning: implicit declaration of function ‘strlen’ [-Wimplicit-function-declaration]
   fail (msg, strlen (msg), "stack smashing detected: terminated");
              ^~~~~~
../../../../gcc-ia16/libssp/ssp.c:229:14: warning: incompatible implicit declaration of built-in function ‘strlen’
../../../../gcc-ia16/libssp/ssp.c:229:14: note: include ‘<string.h>’ or provide a declaration of ‘strlen’
../../../../gcc-ia16/libssp/ssp.c: In function ‘__chk_fail’:
../../../../gcc-ia16/libssp/ssp.c:236:14: warning: incompatible implicit declaration of built-in function ‘strlen’
   fail (msg, strlen (msg), "buffer overflow detected: terminated");
              ^~~~~~
../../../../gcc-ia16/libssp/ssp.c:236:14: note: include ‘<string.h>’ or provide a declaration of ‘strlen’
../../../../gcc-ia16/libssp/gets-chk.c:62:22: error: unknown type name ‘size_t’
 __gets_chk (char *s, size_t slen)
                      ^~~~~~
cc1: warning: target system does not support debug output
make[6]: *** [Makefile:487: ssp.lo] Error 1
make[6]: *** Waiting for unfinished jobs....
make[6]: *** [Makefile:487: gets-chk.lo] Error 1
../../../../gcc-ia16/libssp/memcpy-chk.c:45:15: error: unknown type name ‘size_t’
               size_t len, size_t slen)
               ^~~~~~
../../../../gcc-ia16/libssp/memcpy-chk.c:45:27: error: unknown type name ‘size_t’
               size_t len, size_t slen)
                           ^~~~~~
mv -f .deps/memmove-chk.Tpo .deps/memmove-chk.Plo
make[6]: *** [Makefile:487: memcpy-chk.lo] Error 1
make[6]: Leaving directory '/home/[...]/proj/build-ia16.202501/build-djgpp/ia16-elf/elkslibc/libssp'
make[5]: *** [Makefile:357: all] Error 2
make[5]: Leaving directory '/home/[...]/proj/build-ia16.202501/build-djgpp/ia16-elf/elkslibc/libssp'
make[4]: *** [Makefile:754: multi-do] Error 1
make[4]: Leaving directory '/home/[...]/proj/build-ia16.202501/build-djgpp/ia16-elf/libssp'
make[3]: *** [Makefile:513: all-multi] Error 2
make[3]: Leaving directory '/home/[...]/proj/build-ia16.202501/build-djgpp/ia16-elf/libssp'
make[2]: *** [Makefile:357: all] Error 2
make[2]: Leaving directory '/home/[...]/proj/build-ia16.202501/build-djgpp/ia16-elf/libssp'
make[1]: *** [Makefile:10576: all-target-libssp] Error 2
make[1]: Leaving directory '/home/[...]/proj/build-ia16.202501/build-djgpp'
make: *** [Makefile:872: all] Error 2
Script done.
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