libc-ares-dev 1.15.0-1build1 (s390x binary) in ubuntu focal

 c-ares is a C library that performs DNS requests and name resolution
 asynchronously.
 .
 It is a fork of the library named "ares", with additional features:
  * IPv6 support;
  * extended cross-platform portability;
  * 64-bit clean sources.
 .
 This package contains development files (headers and static libraries).