Thanks to castaway on irc I now know how to turn on DBIC_TRACE from within a debugger session to allow me to examine what’s going on with my DBIx::Class code.

$self->result_source->storage->debug(1) # if $self is a ResultSet
$schema->storage->debug(1) # essentially what you want to do

DBIC_TRACE=1 in front of a script run has always been useful (and the new addition of DBIC_TRACE_PROFILE=console makes it more useful) but being able to turn it off and on from within a debugger session is really handy.