Question regarding magic / antenna DRC: Just ran a demo design through the openlane flow and while it succeeded, I did get 129 Magic_violations and 81 antenna violations. All the magic.drc errors are of this kind:

All nwells must contain metal-connected N+ taps (nwell.4)

I am not designing my own cells or modifying the ones provided in the Skywater libs. Does anyone know how these are caused or how to address them? My design is all HDL. This is with

rc4

of the open lane repo, running in docker.

Try a design exploration over the antenna insertion strategy - values 1, 2, and 3 (3 is best/slowest).

Thanks @Riking28, I see that 3 was the default it was using. You've seen better results sometimes with the 1 / 2? I'll try and see Will also see if I can get caravel building, seems that the configs and build artefacts are there now

3 should be the best one, 1/2 over insert on purpose. You can also try increasing the max iters, or tweaking other parameters like floor planning and global placement density

@drr: You're probably using the latest pdk (skywater, open_pdks) with rc4. Which will cause this https://github.com/efabless/openlane/issues/84#issuecomment-724011544