mha安装manager ,Log::Dispatch ...missing

perl Makefile.PL

*** Module::AutoInstall version 1.03
*** Checking for Perl dependencies...
[Core Features]

DBI ...loaded. (1.609)
DBD::mysql ...loaded. (4.013)
Time::HiRes ...loaded. (1.9721)
Config::Tiny ...loaded. (2.12) - Log::Dispatch ...missing. **- Parallel::ForkManager ...loaded. (0.7.9)
MHA::NodeConst ...loaded. (0.56) ==> Auto-install the 1 mandatory module(s) from CPAN? [y] y *** Dependencies will be installed the next time you type 'make'. *** Module::AutoInstall configuration finished. Writing Makefile for mha4mysql::manager**

perl-Log-Dispatch-2.27-1.el6.noarch
这个perl-Log-Dispatch包已经存在了......为什么还会有missing呢？