The error seems to be in the generated PIR code. From src/gen_actions.pir (lines 6306-6315):
control_3001: .local pmc exception .get_results (exception, $S10) getattribute $P3250, exception, "type" # Null PMC access in type() ne $P3250, 89, control_3001_rethrow getattribute $P3250, exception, "payload" .return ($P3250) control_3001_rethrow: throw exception .end Everything else seems to work, the line with the $/.panic (src/parser/actions.pm:1984) is reached... I don't have sufficient knowledge in PIR or NQP to probe this further. But maybe this helps someone who has.