version: git master(40b81f847f12cf141467a02858d1ac09589cea2f)

configure --help says

```
./configure --help
...
--with-json             don't compile with native JSON support
```

This is the opposite meaning. --with-json means "compile with native
JSON support"

Regards

-- 
Shohei YOSHIDA(syohex@gmail.com)