yosys/prjrellis/nextpnr head bitstream doesn't work

[osresearch]

The bistream produced by a build from head of yosys/prjtrellis/nextpnr doesn't seem to work. The last version that was known-good was:

• Yosys 0.8+411 (git sha1 70d0f389, clang 8.0.0-3 -fPIC -Os) YosysHQ/yosys@70d0f38
• prjtrellis 3311e6d81 f4pga/prjtrellis@3311e6d
• nextpnr-ecp5 -- Next Generation Place and Route (git sha1 19cb4ca) YosysHQ/nextpnr@19cb4ca