yosys error

yosys -ql hardware.log -p 'synth_ice40 -top VexRiscv -blif VexRiscv.blif' VexRiscv.v
ERROR: Found error in internal cell $procdff$946 ($adff) at kernel/rtlil.cc:709:
  attribute \src "VexRiscv.v:2056"
  cell $adff $procdff$946
    parameter \ARST_POLARITY 1'1
    parameter \ARST_VALUE 0
    parameter \CLK_POLARITY 1'1
    parameter \WIDTH 15
    connect \ARST \reset
    connect \CLK \clk
    connect \D \execute_to_memory_INSTRUCTION [14:0]
    connect \Q \memory_to_writeBack_INSTRUCTION [14:0]
  end
make: *** [Makefile:3: hardware.blif] Error 1