Can't create '/usr/local/share/man/man3'
Do not have write permissions on '/usr/local/share/man/man3'
I am not so sure, as I just recently started out using Perl and getting into the shell stuff.....isn't it like that that it seems that you have the "man3" but you are just not able to write in that as your error states that....so if you try out to log into the CPAN shell as root that it should work......
% sudo perl -MCPAN -e shell or locate your man3 file and change the permissions directly on man3.....
please correct me if this is totally nuts...