Another one...
Error while running event integratedCircuitry::on_built_entity (ID 6)
...tegratedCircuitry__/control/compact-combinator-ghost.lua:56: attempt to index local 'entity' (a nil value)
stack traceback:
...tegratedCircuitry__/control/compact-combinator-ghost.lua:56: in function 'indestructible'
...tegratedCircuitry__/control/compact-combinator-ghost.lua:13: in function 'build'
integratedCircuitry/libs/control/entities.lua:277: in function 'entities_build'
integratedCircuitry/control.lua:64: in function <integratedCircuitry/control.lua:62>
This one was when using a blueprint to copy-paste an IC.