Error while make results

[Agalakdak]

I tried to run the benchmark but I got an error, what could be the problem?

bench.h:84:13: error: conflicting types for ‘socklen_t’; have ‘int’

make results
gmake[1]: Entering directory '/home/user/lmbench/src'
gcc -O -DSYS5 -Dvalloc=malloc -DS_IFIFO=S_IFFIFO -c lib_tcp.c -o ../bin/x86_64-linux-gnu/lib_tcp.o
In file included from lib_tcp.c:9:
bench.h:84:13: error: conflicting types for ‘socklen_t’; have ‘int’
84 | typedef int socklen_t;
| ^~~~~~~~~
In file included from bench.h:17:
/usr/include/unistd.h:274:21: note: previous declaration of ‘socklen_t’ with type ‘socklen_t’ {aka ‘unsigned int’}
274 | typedef __socklen_t socklen_t;
| ^~~~~~~~~
gmake[1]: *** [Makefile:227: ../bin/x86_64-linux-gnu/lib_tcp.o] Error 1
gmake[1]: Leaving directory '/home/user/lmbench/src'
make: *** [Makefile:114: lmbench] Error 2