anchor.diff:      useLocalHostname,
       query ? if useLocalHostname then "local-ipv4" else "public-hostname",
       recordType ? if useLocalHostname then "A" else "CNAME"
  -  }: pkgs.writeScript "ec2-register-hostname-${zone}" ''
  -    #!${bash}
  +  }: sdk.writeBashScriptOverride ["SC2046"] "ec2-register-hostname-${zone}" ''
  +
       date=$(${curl} -I https://route53.amazonaws.com/date | ${awk} '/^Date: / {sub("Date: ", "", $0); sub("\\r", "", $0); print $0}')
   
       iam="${iamCredentialName}"
  
positive.code:     set -- $(${wget} http://169.254.169.254/latest/meta-data/iam/security-credentials/${iamCredentialName} \
                | ${jq} -r '.SecretAccessKey, .AccessKeyId, .Token')
  
      signature=$(echo -n $date | ${openssl} dgst -binary -sha1 -hmac $1 | ${base64})
      auth_header="X-Amzn-Authorization: AWS3-HTTPS AWSAccessKeyId=$2,Algorithm=HmacSHA1,Signature=$signature"
      record_value=$(${wget} http://169.254.169.254/latest/meta-data/${query})
  
  
negative.code: 
    ec2-autohostname = ''
      ${ip} route delete blackhole 169.254.169.254 2>/dev/null || true
      # registering route 53 hostnames if any:
      echo ${concatStringsSep " " (
          mapAttrsToList (_: args: retry-wrapper (register-hostname {
  