Hi, I'm testing prjxray with vivado 2019, I know that is not supported, so it might not be worth your time, but I'm having a different error
from the ones listed in https://github.com/SymbiFlow/prjxray/issues/14

What I did was running make copy inside "prjxray/minitests/roi_harness"
"
ERROR: [DRC RTSTAT-5] Partial antennas: 4 net(s) have a partial antenna. The problem bus(es) and/or net(s) are din_IBUF[2], din_IBUF[3], din_IBUF[5], and din_IBUF[7].
"