@Tim 'mithro' Ansell, I'm thinking about interfacing problems that affect two or more repositories (e.g., magic, xschem, ngspice, and sky130PDK). Since there are many different ways to cobble the tools together, some sort of meta-repo that contains interfaces agreed on and verified by the principal developers of the tools involved would probably save time overall, by weeding out all the workarounds that only almost solve the compatibility problems.