Well, it seems that “it uses CPAN,” but in a slightly different way. There is no .cpan directory in the home directory of the site user, and there is no subdirectory anywhere (at home) named e.g. build. The site user's modules are, however, installed in ~/perl, and I know that CPAN was used to get them there.

So, I basically need the incantation to “get me to the CPAN shell,” but I don't want to have to “figure it out” if somebody else has already done so.