hello, anyone know if there there is some sort of routing keepout or halo placed around macros by default?

Check variables

PL_MACRO_HALO

and

PL_MACRO_CHANNEL

thank you, will do

Normally if SRAM macros placed, to avoid DRC errors

GRT_OBS

used. But i'm not quite understand your requirement. Tagging @Matt Liberty for further help

i'm just trying to understand why the pins on my custom layout aren't accessible. it looks like there's enough space between them but it's possible that the density just means the router gives up.

https://github.com/The-OpenROAD-Project/OpenROAD/pull/675 something similar

possibly, i'm not sure i understand what that bug is about

pin access problems are local to the macro itself and not about density (unless you have a cell abutting the macro which would be weird)

thanks @Matt Liberty - do you know more about how access is negotiated at the cells? how hard does the router try to find a path to a pin? or maybe how to modify the cell to make it easier for the router?

It is hard to say without seeing the problem. You could either open a GH issue with test case or try out: detailed_route_debug -pa -pa_markers -pin <inst>:<pin> and run OR detailed routing in the GUI. It will stop and show you the drc errors found while trying to access that pin

the pins themselves are drc clean and further apart than metal 3 pitch, for example. which repo is most appropriate for this issue to be filed in?

I don't know where the pin in question is in that image. Also that is gds not lef so it is less helpful

good to know, i'll mark them