Has anybody used the example_por or run example_por_tb.sch in xschem? I opened the example project, but I wasn't able to descend into any of the buffer schematics. Looking at the folder they referenced, I only have .sym files in there after following the video to install the pdk using openpdk. Is there any way to add those schematics into the folder without reinstalling the entire pdk?

These are standard cells, so they don't have a schematic (because SkyWater didn't provide any schematics in any open source format). For SPICE simulation they rely on including the SPICE library for the standard cell set from the installed sky130A PDK.

That makes sense. Thanks!

@User As Tim explained these are standard cells, Xschem knows these are primitive devices and does not expect a schematic for them, the stdcell netlist is included as a text file from skywater-pdk. The standard cells symbols for Xschem were generated from these text files to guarantee correct pin ordering.