r-cran-httpuv 1.5.2+dfsg-1 (s390x binary) in ubuntu focal

 The R package httpuv provides low-level socket and protocol support for
 handling HTTP and WebSocket requests directly from within R. It is primarily
 intended as a building block for other packages, rather than making it
 particularly easy to create complete web applications using httpuv alone.
 httpuv is built on top of the libuv and http-parser C libraries, both of which
 were developed by Joyent, Inc.