Hmm ... It's impossible ;-) This RPM doesn't exist on any FTP server

Provides :
libevent-2_1-devel
libevent-devel
libevent-devel
libevent-devel(x86-64)
libevent2-devel
pkgconfig(libevent)
pkgconfig(libevent_core)
pkgconfig(libevent_extra)
pkgconfig(libevent_openssl)
pkgconfig(libevent_pthreads)

Requires :

rpmlib(FileDigests) <= 4.6.0-1
rpmlib(CompressedFileNames) <= 3.0.4-1
libevent_pthreads-2.1.so.6()(64bit)
libevent_extra-2.1.so.6()(64bit)
libevent-2.1.so.6()(64bit)
/usr/bin/pkg-config
libevent_core-2.1.so.6()(64bit)
rpmlib(PayloadIsXz) <= 5.2-1
/usr/bin/env
rpmlib(PayloadFilesHavePrefix) <= 4.0-1
pkgconfig(libevent)
libevent = 2.1.8
libevent_openssl-2.1.so.6()(64bit)

Content of RPM :
/usr/bin/event_rpcgen.py
/usr/include/evdns.h
/usr/include/event.h
/usr/include/event2
/usr/include/event2/buffer.h
/usr/include/event2/buffer_compat.h
/usr/include/event2/bufferevent.h
/usr/include/event2/bufferevent_compat.h
/usr/include/event2/bufferevent_ssl.h
/usr/include/event2/bufferevent_struct.h
/usr/include/event2/dns.h
/usr/include/event2/dns_compat.h
/usr/include/event2/dns_struct.h
/usr/include/event2/event-config.h
/usr/include/event2/event.h
/usr/include/event2/event_compat.h
/usr/include/event2/event_struct.h
/usr/include/event2/http.h
/usr/include/event2/http_compat.h
/usr/include/event2/http_struct.h
/usr/include/event2/keyvalq_struct.h
/usr/include/event2/listener.h
/usr/include/event2/rpc.h
/usr/include/event2/rpc_compat.h
/usr/include/event2/rpc_struct.h
/usr/include/event2/tag.h
/usr/include/event2/tag_compat.h
/usr/include/event2/thread.h
/usr/include/event2/util.h
/usr/include/event2/visibility.h
There is 16 files more in these RPM.