Compilation failure on Void Linux

[Majora320]

In Void Linux, the dns_sd.h header is installed to /usr/include/avahi-compat-libdns_sd/dns_sd.h, but the gem assumes that the header is installed to <something>/include/dns_sd.h. Therefore, sudo gem install dnssd -- --with-dnssd-dir=/usr/include/avahi-compat-libdns_sd/ fails, and the mkmf.log file shown the compiler trying to include /usr/include/avahi-compat-libdns_sd//include.