Ensure zeroconf can be loaded when the system disables IPv6 (python-zeroconf#624)

bdraco · web-flow · commit 42d53c7c04a7 · 2021-06-14T16:27:30.000-10:00
diff --git a/zeroconf/const.py b/zeroconf/const.py
@@ -38,7 +38,10 @@
 _MDNS_ADDR = '224.0.0.251'
 _MDNS_ADDR_BYTES = socket.inet_aton(_MDNS_ADDR)
 _MDNS_ADDR6 = 'ff02::fb'
-_MDNS_ADDR6_BYTES = socket.inet_pton(socket.AF_INET6, _MDNS_ADDR6)
+try:
+    _MDNS_ADDR6_BYTES = socket.inet_pton(socket.AF_INET6, _MDNS_ADDR6)
+except OSError:  # can't use AF_INET6, IPv6 is disabled
+    pass
 _MDNS_PORT = 5353
 _DNS_PORT = 53
 _DNS_HOST_TTL = 120  # two minute for host records (A, SRV etc) as-per RFC6762
