添加libresolv.tbd库,即可解决问题
Undefined symbols for architecture arm64:
"_dns_parse_resource_record", referenced from:
-[JPUSHSRVResolver processRecord:length:] in jpush-iOS-2.2.0.a(JPUSHSRVResolver.o)
"_dns_free_resource_record", referenced from:
-[JPUSHSRVResolver processRecord:length:] in jpush-ios-2.2.0.a(JPUSHSRVResolver.o)
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)