The recipe I've used to simulate digital standard cell models in an xschem schematic is a code block with ".include $::SKYWATER_STDCELLS/sky130_fd_sc_hd.spice" inside. I am converting my testbenches into CACE format, and this results in an ngspice error for ".include filename missing" when running a characterization study. Is this a problem that's been run into yet?

Okay, glad you found a solution. CACE just uses the standard sky130 xschemrc file, so I would expect it to expand the SKYWATER_STDCELLS variable correctly. I'm not sure why it requires its own top-level code block.