LVS: internal error after align

[klayoutmatthias]

After using "align" in a LVS runset, the following error was encountered:

This situation cannot happen in a freshly extracted netlist, but "align" may be somehow able to trigger it.

[klayoutmatthias]

I assume problem was caused (I don't have a testcase) by a schematic netlist, in which two pins got connected inside a subcircuit. This case was not handled so far, as KLayout cannot generate it in the extraction step.

The solution is to join nets connected through a subcircuit when this subcircuit is flattened.