The hint is this:
Note (probably harmless): No library found for -levent
Install Event::Lib on my box thru CPAN module reports "No library found for -levent" , so I tried to install it thru source,and specified the location of libevent.so like:

perl Makefile.PL INC=-I/usr/local/include LIBS="-L/usr/local/lib -leve
+nt"
[download]

then all the test is successful.
Although make test with Event::Lib successfully, 'make verify' with libevent still reports FAILED, this is weird.
Whatever, Event::Lib can work well in my box now:)