Build Heartbleed exploit by HackerFantastic on Mac OS https://raw.githubusercontent.com/HackerFantastic/Public/master/exploits/heartbleed.c

build-heartbleed-osx.sh

#!/bin/sh

# Clone OpenSSL repository
# Credits to https://github.com/robertdavidgraham/heartleech
git clone git://git.openssl.org/openssl.git
cd openssl
# Build 64-bit library on Mac OS
./configure darwin64-x86_64-cc
make depend
make

# Download latest heartbleed exploit by HackerFantastic
wget https://raw.githubusercontent.com/HackerFantastic/Public/master/exploits/heartbleed.c
# Compile it with Clang using compiled OpenSSL
cc -o heartbleed *.a -lcrypto -I ./include -Wno-return-type heartbleed.c

Same issue here.