I discovered that DBIx::Class::Schema::Loader had been filling my table classes with lines of the form __PACKAGE__->add_unique_constraint(['id'], undef); erroneously, due to someone's inadvertently iterating over %hash rather than keys %hash. Not only were these lines redundant in the case of a primary key, but the parameters are supposed to be a name and a list of columns: thus I had a lot of constraints with ARRAY(0x...) as names and no columns. This was thoroughly breaking $schema->deploy, as it was trying to create indices with garbage names that looked like functions. I have, obviously, removed them all.
In the process, I have done something I've been meaning to do for a while: cleaned up the source in every single file to match my usual style. No auto-gen comment, no redundant loading of PK::Auto, no double-newline after the 1;, proper POD, use of qw// for passing lists, etc. This is actually a teeny part of my db cleanup tracking bug. (#58)