Even the simplest json can not be parsed on FreeBSD or OS X

curl -O https://raw.githubusercontent.com/step-/JSON.awk/master/JSON.awk
cat <<EOF > x.json
{
    "name": "latest"
}
EOF
awk -f JSON.awk x.json

produces

x.json: expected <string> but got <"> at input token 2
{ <<">> 
x.json: expected <value> but got <a> at input token 1
<<a>> m e ": " l a t e s t " 
invalid: x.json
expected <string> but got <"> at input token 2
{ <<">> 
expected <value> but got <a> at input token 1
<<a>> m e ": " l a t e s t "

This is on FreeBSD with awk version 20121220 (FreeBSD) as well as on Darwin with awk version 20070501.