I take it that since you've got this far you've installed the developer tools, which I think was tricycle's problem.

I've been having related problems doing pretty much the same thing. In the end I installed the DBI and DBD::mysql packages manually. They seem to work fine. The problem I've been seeing with this and other CPAN-based installs is that newer modules apparently depend on perl 5.6.1 rather than the 5.6.0 that ships with OSX. I've compiled perl 5.6.1 and 5.7.2 but they fail a few of the tests run by make test (including one of the POSIX tests) so I'm a bit leery of actually installing them.

On a side note, the fink project is apparently working on providing the DBI and DBD modules; the relevant modules are in the current-unstable tree. Wait a while and the problem might go away :-)

Tim

Update: For completeness, I'll just add this pointer to a previous, more comprehensive thread on MacOSX and perl.

Update^2 (belated): Having installed perl 5.6.1 using the instructions codified here (which basically say: ignore my above concerns :P), I've found that the perl -MCPAN -e shell route works (almost) flawlessly. The only significant problem so far has been the DB_File module, which is one of the modules which originally failed make test anyway.

HTH, Tim