digraph G {
"$project.bit" [shape=box,style=filled]
"$project.json" [shape=box,style=filled]
yosys [label="yosys\narch=ice40\noutput_format=json"]
nextpnr [label="nextpnr\narch=ice40"]

frontends -> yosys;
yosys -> nextpnr;
yosys -> "$project.json" [label="pnr==none"];
nextpnr -> icetime;
nextpnr -> icebox_stat;
nextpnr -> icepack;
icepack -> "$project.bit";
}