gistfile1.txt

(blead) clifford:~/perlfromperlorg $ make malloc.o
clang -c -DPERL_CORE -D_REENTRANT -D_GNU_SOURCE -DDEBUGGING -fno-strict-aliasing -pipe -fstack-protector -I/usr/local/include -D_LARGEFILE_S
OURCE -D_FILE_OFFSET_BITS=64 -D_FORTIFY_SOURCE=2 -std=c89 -O3 -Wall -Werror=declaration-after-statement -Wextra -Wc++-compat -Wwrite-strings
 malloc.c
malloc.c:257:4: error: "MYMALLOC is not defined"
#  error "MYMALLOC is not defined"
   ^
malloc.c:985:13: warning: implicit declaration of function 'malloced_size' [-Wimplicit-function-declaration]
    *size = malloced_size(pv) + M_OVERHEAD;
            ^

Using perlbrew, I tried make malloc.o on 5.10.0, 5.14.4 and 5.20.3. Same (or very similar) errors.

My hunch is that make malloc.o is not a valid make target and never has been.