examples/ecp5_evn failed to build with oss-cad-suite 2022-03-27

[minecraft2048]

I've run make and it failed to build with this error:

2.49. Printing statistics.

=== top ===

   Number of wires:                 89
   Number of wire bits:            715
   Number of public wires:          15
   Number of public wire bits:     133
   Number of memories:               0
   Number of memory bits:            0
   Number of processes:             12
   Number of cells:                 52
     $add                            3
     $eq                            28
     $logic_and                      2
     $lt                             8
     $mux                            1
     $sub                           10

2.50. Executing CHECK pass (checking for obvious problems).
Checking module top...
Found and reported 0 problems.

2.51. Executing JSON backend.
ERROR: Module top contains processes, which are not supported by JSON backend (run `proc` first).
make: *** [Makefile:7: blinky.json] Error 1
rm blinky.json

Possibly related issue: https://github.com/YosysHQ/prjtrellis/issues/182

[gatecat]

Hopefully this is fixed with 46f50f7