This a md5 implementation of the nickjj/gowatcher script. The reason that I've decided to use md5sum instead inotify-tools it's because I'm using sync folder through Vagrant.

gowatcher-md5.sh

#!/bin/bash

# go $1 $2 &

sum="0"
while true;
do
  tmp=`find . -type f -name "*.go" -exec md5sum {} + | awk '{print $1}' | sort | md5sum | awk '{print $1}'`
  if [ "$sum" != "$tmp" ]
    then
      echo "Sum: $sum (changed)"
      pkill -9 -f a.out > /dev/null 2>&1
      go install
      go $1 $2 &
      sum=$tmp
  fi
  sleep 1
done