This problem may occurred when trying to run Perl script with database connection error like below,

install_driver(mysql) failed: Can't locate DBD/ in @INC (@INC contains: /usr/local/lib64/perl5 /usr/local/share/perl5 /usr/lib64/perl5/vendor_perl /usr/share/perl5/vendor_perl /usr/lib64/perl5 /usr/share/perl5 .) at (eval 3) line 3.
Perhaps the DBD::mysql perl module hasn't been fully installed,
or perhaps the capitalisation of 'mysql' isn't right.
Available drivers: DBM, ExampleP, File, Gofer, Proxy, SQLite, Sponge.
 at ./eximlogs line 17

We have to configure DBD-mysql module with your Perl, the DBD-mysql module is manually downloading and installing in your server, this may be the best method for should be fixed error.

/scripts/perlmods -l  :  List out installed modules

First, you have to check the dbd-mysql has been configured with Perl, once executed below Cpanel script will be showing  DBD::mysql=4.022=
root@host [~]# /scripts/perlmods -l | grep mysql

If you could not found it trying to install and configure dbd-mysql  as below steps.
Download package from the url using wget command and extract tar files
# wget
# tar zfvxp DBD-mysql-4.022.tar.gz
# cd  DBD-mysql-4.022
# perl Makefile.PL
# make install clean
Now, configured DBD::mysql=4.022  in your server.

Another way to install using cpan, just read and give the command Below ,
# perl -MCPAN -e shell
cpan> install DBD::mysql

Wait for few moments until installation completed and can check the module installed it.