Can't install Perl DBI or DBD::mysql after Mountain Lion upgrade

Question

I recently upgraded to Mountain Lion and found that my Perl DBI scripts stopped working, with the error message "Can't locate DBD/mysql.pm in @INC".
The last time this happened, after upgrading to Lion, the solution was to install the new version of Xcode. Then I was able to use the Perl CPAN module to install DBI and DBD::mysql. (MySQL is already installed and running with no problem on the Mountain Lion machine.)
Now I have installed Xcode 4.5.1, and tried
mrb% sudo perl -MCPAN -e shell
[then CPAN configures itself]
cpan[1]> install DBI
and it fails with this final message:
/System/Library/Perl/5.12/darwin-thread-multi-2level/CORE/perl.h:583:11: fatal error:
      'sys/types.h' file not found
#       include <sys/types.h>
                ^
1 error generated.
make: *** [Perl.o] Error 1
  TIMB/DBI-1.622.tar.gz
  /Developer/usr/bin/make -- NOT OK
'YAML' not installed, will not store persistent state
Running make test
  Can't test without successful make
Running make install
  Make had returned bad status, install seems impossible
Failed during this command:
TIMB/DBI-1.622.tar.gz                        : make NO
Can anybody help?

Answer 1

Here is a link to a resolution in Lion. It may also solve your Mountain Lion Perl DBD issue as well.
If you run the command below before executing your Perl script the library is found and all is well!
export DYLD_LIBRARY_PATH="/usr/local/mysql/lib:$DYLD_LIBRARY_PATH"
Put this in your .bashrc or .bash_profile.
On Apple StackExchange, Matthew Weiss had another approach.
I found on another website the following command
$ sudo perl -MCPAN -e 'CPAN::Shell->notest(install => CPAN::Shell->r)'
This updated all my perl modules and all is back to normal. Not sure why or what, but don't care that it is working now.