SyncValsverifier → artifact → classifier → verdict
SyncVals · Trajectory

hash-message-padder

claude-code claude-opus-4-8 ✗ failed HARNESS_ERROR ↑ View task
Solved from the instruction alone, tests/ and solution/ were withheld from the agent's workspace and restored only for grading.
Reward = tests/test.sh exit code (0 → resolved); the classification below is post-hoc and cannot change it.
Classification , post-hoc; cannot change the reward
HARNESS_ERRORInfrastructure failure, the agent never ran properly. Not a signal about agent or task.
SubtypeVerifier Runtime Tamper Guard
Evidenceverifier/test-stdout.txt contains: "FAIL: tampered GRADER_HOME/runtime detected -> failing closed (score 0)" and result.json shows reward 0.0. The verifier exited before compile/simulation, so no behavioral mismatch from tests/test.sv or ref.sv was reported.
Root causeThe trial failed because the verifier harness detected an unsafe grader/runtime path state and failed closed before evaluating /app/dut.sv. This does not reveal an underspecified instruction or brittle task test.
RecommendationN/A - infrastructure/harness issue, not a task-spec problem
Trajectory
Tool-by-tool agent trajectory
6 tool calls · 2 tool types · 11 steps
Design a SystemVerilog module named TopModule that splits a stream of message bytes across four parallel lanes, pads each lane independently, and frames the result into 64-bit blocks, with valid/ready handshakes on both the byte input and the block output. Ports, one bit each unless noted: inputs clk, rst, start_i, byte_i [7:0], byte_valid_i, last_i, block_ready_i; outputs block_o [63:0], block_valid_o, byte_ready_o, done_o, busy_o. All five outputs are registered. rst is synchronous active high: every output clears to 0 except byte_ready_o which clears to 1. block_o is compared only while block_valid_o is high. A byte is accepted on a rising edge where byte_valid_i and byte_ready_o are both high. start_i accompanies the first accepted byte, last_i the final one. The message length is its accepted-byte count, 1 to 8191. Number the accepted bytes from zero in arrival order. Byte k belongs to lane k mod 4. Within a lane the bytes keep their arrival order and pack eight per block, big-endian, the earliest byte in block_o[63:56]. Each lane is padded on its own byte stream. Append 0x80 in the byte position immediately after that lane's last byte, fill the rest with zero, and place that lane's length in bits, which is eight times the number of bytes routed to the lane, as a 16-bit big-endian value in byte6 and byte7 of the lane's final block. Emit the fewest blocks per lane that hold the lane's bytes, the marker, the fill and the length. When a lane's byte count is a multiple of eight, its 0x80 and length occupy one additional all-padding block. When the block holding a lane's last byte has six or seven byte positions filled, the length does not share it: that block carries the bytes, 0x80 and zero fill, and a following block holds only the length. A lane with no bytes still emits one block holding 0x80, zero fill and a zero length. Index the blocks of each lane from zero. Emit all four lanes' block 0, then all four lanes' block 1, and so on; within an index emit lane 0 first through lane 3. Skip a lane at indices beyond its block count. block_valid_o is high while a block is presented and a block is accepted on a rising edge where block_valid_o and block_ready_i are both high; while it is stalled block_o and block_valid_o hold. Present one block at a time. byte_ready_o is high while bytes are accepted and low while blocks are leaving. busy_o is high from the first accepted byte until the final block is accepted, low otherwise. The final block is the highest index reached by any lane, taken in the highest-numbered lane that reaches it. done_o is high for the cycles that block is presented, so on its accepting edge block_valid_o, block_ready_i and done_o are all high. Put the implementation in /app/dut.sv with the module named TopModule and exactly this port list. It is compiled with iverilog -g2012 against a held-back reference and simulated under randomized stimulus that drives the byte side and randomly stalls the block side; the design must match the reference on every output on every clock edge for every sample. Use plain synthesizable SystemVerilog: module/endmodule, always/assign, localparam, reg, wire, logic and functions. Do not use preprocessor directives (include, define, ifdef, ifndef, undef, the token-paste operator), do not call simulator system tasks ($display, $write, $finish, $stop, $system, $fopen, $fwrite, $fdisplay, $fread, $fgets, $feof, $readmem, $writemem, $dumpfile, $dumpvars, $fatal, $exit, $error, $warning, $assert), do not use force or release, and do not import DPI-C; the verifier rejects the submission before simulation if any of these appear in /app/dut.sv.
I'll design this carefully. Let me first reason through the padding formula and timing, then write the module. Key facts I've derived: - Byte k → lane k mod 4; lengths satisfy L0≥L1≥L2≥L3. - Blocks per lane N_r = ⌊(L_r+10)/8⌋ = ⌈(L_r+3)/8⌉ (every lane emits ≥1 block). - Length (16-bit BE = 8·L_r) sits in the last two byte positions of the lane's final block; 0x80 right after last byte; the formula naturally handles the "6/7 filled → separate block" and "multiple-of-8 → extra block" cases. - Emission is index-major (all lanes' block 0, then block 1, …), lane 0→3 within an index; since N is non-increasing the valid lanes at each index form a prefix. - Final block = (final_lane, maxN−1) where maxN=N0 and final_lane = highest lane with N_r=N0; this is exactly the last block in sequence, so done_o = "presenting the last block." - Zero-latency handoff: the cycle after the last byte is accepted, block_valid_o goes high with block(0,0). The only hazard (block(0,0) needing the just-accepted last byte when it lands in lane 0's first block) is handled by substituting byte_i during that one transition. Let me write it.
write · /app/dut.sv
module TopModule (
    input  wire        clk,
    input  wire        rst,
    input  wire        start_i,
    input  wire [7:0]  byte_i,
    input  wire        byte_valid_i,
    input  wire        last_i,
    input  wire        block_ready_i,
    output reg  [63:0] block_o,
    output reg         block_valid_o,
    output reg         byte_ready_o,
    output reg         done_o,
    output reg         busy_o
);

    // ---------------------------------------------------------------
    // States
    // ---------------------------------------------------------------
    localparam [1:0] S_IDLE = 2'd0;
    localparam [1:0] S_RECV = 2'd1;
    localparam [1:0] S_EMIT = 2'd2;

    reg [1:0]  state;

    // Per-lane data storage (max lane length 2048 bytes)
    reg [7:0]  mem [0:3][0:2047];

    // Per-lane byte counts
    reg [12:0] lane_len [0:3];

    // Receive-side rotating lane pointer
    reg [1:0]  recv_lane;

    // Emission pointer
    reg [1:0]  cur_lane;
    reg [8:0]  cur_i;

    // ---------------------------------------------------------------
    // Number of blocks for a lane of L bytes: floor((L+10)/8)
    // ---------------------------------------------------------------
    function automatic [8:0] calcN(input [12:0] L);
        begin
            calcN = (L + 13'd10) >> 3;
        end
    endfunction

    // Combinational lane block counts (valid/stable while emitting)
    wire [8:0] N0 = calcN(lane_len[0]);
    wire [8:0] N1 = calcN(lane_len[1]);
    wire [8:0] N2 = calcN(lane_len[2]);
    wire [8:0] N3 = calcN(lane_len[3]);

    // Max block count is lane0 (lengths are non-increasing)
    wire [8:0] maxN   = N0;
    wire [8:0] maxN_m1 = N0 - 9'd1;

    // Highest-numbered lane that reaches the max index
    wire [1:0] final_lane = (N3 == N0) ? 2'd3 :
                            (N2 == N0) ? 2'd2 :
                            (N1 == N0) ? 2'd1 : 2'd0;

    // Block count of lane (cur_lane+1), used to test prefix continuation
    wire [8:0] Nnext = (cur_lane == 2'd0) ? N1 :
                       (cur_lane == 2'd1) ? N2 : N3;

    // ---------------------------------------------------------------
    // Build a block for (lane, idx) from committed memory / lengths
    // ---------------------------------------------------------------
    function automatic [63:0] build_block(input [1:0] lane, input [8:0] idx);
        reg [12:0] L;
        reg [8:0]  nb;
        reg [12:0] nb8;
        reg [15:0] lenb;
        reg [63:0] blk;
        reg [12:0] gp;
        reg [7:0]  bv;
        integer    b;
        begin
            L    = lane_len[lane];
            nb   = calcN(L);
            nb8  = {nb, 3'b000};
            lenb = {L, 3'b000};
            blk  = 64'b0;
            for (b = 0; b < 8; b = b + 1) begin
                gp = ({idx, 3'b000}) + b[12:0];
                if (gp < L)
                    bv = mem[lane][gp[10:0]];
                else if (gp == L)
                    bv = 8'h80;
                else if (gp == (nb8 - 13'd2))
                    bv = lenb[15:8];
                else if (gp == (nb8 - 13'd1))
                    bv = lenb[7:0];
                else
                    bv = 8'h00;
                blk[(7-b)*8 +: 8] = bv;
            end
            build_block = blk;
        end
    endfunction

    // ---------------------------------------------------------------
    // Build block (0,0) at the transition edge, substituting the
    // just-accepted last byte if it lands in lane 0's first block.
    // ---------------------------------------------------------------
    function automatic [63:0] build_trans;
        reg [12:0] L0;
        reg [12:0] wpos;
        reg [8:0]  nb;
        reg [12:0] nb8;
        reg [15:0] lenb;
        reg [63:0] blk;
        reg [12:0] gp;
        reg [7:0]  bv;
        integer    b;
        begin
            L0   = lane_len[0] + ((recv_lane == 2'd0) ? 13'd1 : 13'd0);
            wpos = lane_len[0];
            nb   = calcN(L0);
            nb8  = {nb, 3'b000};
            lenb = {L0, 3'b000};
            blk  = 64'b0;
            for (b = 0; b < 8; b = b + 1) begin
                gp = b[12:0];
                if (gp < L0) begin
                    if ((recv_lane == 2'd0) && (gp == wpos))
                        bv = byte_i;
                    else
                        bv = mem[0][gp[10:0]];
                end
                else if (gp == L0)
                    bv = 8'h80;
                else if (gp == (nb8 - 13'd2))
                    bv = lenb[15:8];
                else if (gp == (nb8 - 13'd1))
                    bv = lenb[7:0];
                else
                    bv = 8'h00;
                blk[(7-b)*8 +: 8] = bv;
            end
            build_trans = blk;
        end
    endfunction

    // ---------------------------------------------------------------
    // Main sequential logic (all outputs registered)
    // ---------------------------------------------------------------
    always @(posedge clk) begin : main
        reg [1:0] nl;
        reg [8:0] ni;
        if (rst) begin
            state         <= S_IDLE;
            block_o       <= 64'b0;
            block_valid_o <= 1'b0;
            byte_ready_o  <= 1'b1;
            done_o        <= 1'b0;
            busy_o        <= 1'b0;
            lane_len[0]   <= 13'd0;
            lane_len[1]   <= 13'd0;
            lane_len[2]   <= 13'd0;
            lane_len[3]   <= 13'd0;
            recv_lane     <= 2'd0;
            cur_lane      <= 2'd0;
            cur_i         <= 9'd0;
        end else begin
            case (state)
                // ---------------------------------------------------
                S_IDLE: begin
                    if (byte_valid_i && byte_ready_o) begin
                        // First accepted byte -> lane 0
                        mem[0][0]   <= byte_i;
                        lane_len[0] <= 13'd1;
                        recv_lane   <= 2'd1;
                        busy_o      <= 1'b1;
                        if (last_i) begin
                            // Single-byte message: go straight to emit
                            state         <= S_EMIT;
                            byte_ready_o  <= 1'b0;
                            block_valid_o <= 1'b1;
                            done_o        <= 1'b0;
                            cur_lane      <= 2'd0;
                            cur_i         <= 9'd0;
                            block_o       <= build_trans();
                        end else begin
                            state <= S_RECV;
                        end
                    end
                end
                // ---------------------------------------------------
                S_RECV: begin
                    if (byte_valid_i && byte_ready_o) begin
                        mem[recv_lane][lane_len[recv_lane][10:0]] <= byte_i;
                        lane_len[recv_lane] <= lane_len[recv_lane] + 13'd1;
                        recv_lane <= (recv_lane == 2'd3) ? 2'd0 : (recv_lane + 2'd1);
                        if (last_i) begin
                            state         <= S_EMIT;
                            byte_ready_o  <= 1'b0;
                            block_valid_o <= 1'b1;
                            done_o        <= 1'b0;
                            cur_lane      <= 2'd0;
                            cur_i         <= 9'd0;
                            block_o       <= build_trans();
                        end
                    end
                end
                // ---------------------------------------------------
                S_EMIT: begin
                    if (block_valid_o && block_ready_i) begin
                        if ((cur_lane == final_lane) && (cur_i == maxN_m1)) begin
                            // Final block accepted: finish
                            state         <= S_IDLE;
                            block_valid_o <= 1'b0;
                            done_o        <= 1'b0;
                            busy_o        <= 1'b0;
                            byte_ready_o  <= 1'b1;
                            lane_len[0]   <= 13'd0;
                            lane_len[1]   <= 13'd0;
                            lane_len[2]   <= 13'd0;
                            lane_len[3]   <= 13'd0;
                            recv_lane     <= 2'd0;
                            cur_lane      <= 2'd0;
                            cur_i         <= 9'd0;
                        end else begin
                            // Advance to the next slot
                            if ((cur_lane < 2'd3) && (cur_i < Nnext)) begin
                                nl = cur_lane + 2'd1;
                                ni = cur_i;
                            end else begin
                                nl = 2'd0;
                                ni = cur_i + 9'd1;
                            end
                            cur_lane <= nl;
                            cur_i    <= ni;
                            block_o  <= build_block(nl, ni);
                            done_o   <= ((nl == final_lane) && (ni == maxN_m1));
                        end
                    end
                end
                // ---------------------------------------------------
                default: state <= S_IDLE;
            endcase
        end
    end

endmodule
Now let me verify it compiles and simulates correctly against a reference model I'll write for testing.

Syntax-check dut.sv with iverilog

shell
iverilog -g2012 -o /tmp/dut_syntax.out dut.sv 2>&1 && echo "COMPILE OK"
output
COMPILE OK

[stdout]
COMPILE OK
Compiles. Now let me build a self-checking testbench with an independent golden model to validate padding, ordering, and handshakes under randomized stimulus with block-side stalls.
write · /tmp/tb.sv
module tb;
    reg clk, rst, start_i, byte_valid_i, last_i, block_ready_i;
    reg [7:0] byte_i;
    wire [63:0] block_o;
    wire block_valid_o, byte_ready_o, done_o, busy_o;

    TopModule dut(.clk(clk), .rst(rst), .start_i(start_i), .byte_i(byte_i),
        .byte_valid_i(byte_valid_i), .last_i(last_i), .block_ready_i(block_ready_i),
        .block_o(block_o), .block_valid_o(block_valid_o), .byte_ready_o(byte_ready_o),
        .done_o(done_o), .busy_o(busy_o));

    always #5 clk = ~clk;

    // ---- golden expected block sequence storage ----
    reg [63:0] exp_blk [0:5000];
    reg        exp_done [0:5000];
    integer    exp_n;

    // message bytes
    reg [7:0] msg [0:8191];
    integer   msglen;

    integer seed;
    integer errors;

    // per-lane byte store for golden
    reg [7:0] lmem [0:3][0:2047];
    integer   llen [0:3];

    task compute_golden;
        integer i, r, N[0:3], maxN, flane, idx, lane, b, gp, L, nb, valid_lanes;
        reg [15:0] lenb;
        reg [63:0] blk;
        begin
            llen[0]=0; llen[1]=0; llen[2]=0; llen[3]=0;
            for (i=0;i<msglen;i=i+1) begin
                r = i % 4;
                lmem[r][llen[r]] = msg[i];
                llen[r] = llen[r]+1;
            end
            for (r=0;r<4;r=r+1) N[r] = (llen[r]+10)/8;
            maxN = N[0];
            flane = (N[3]==N[0])?3:(N[2]==N[0])?2:(N[1]==N[0])?1:0;
            exp_n = 0;
            for (idx=0; idx<maxN; idx=idx+1) begin
                for (lane=0; lane<4; lane=lane+1) begin
                    if (idx < N[lane]) begin
                        L = llen[lane];
                        nb = N[lane];
                        lenb = L*8;
                        blk = 0;
                        for (b=0;b<8;b=b+1) begin
                            gp = idx*8+b;
                            if (gp < L) blk[(7-b)*8 +: 8] = lmem[lane][gp];
                            else if (gp == L) blk[(7-b)*8 +: 8] = 8'h80;
                            else if (gp == nb*8-2) blk[(7-b)*8 +: 8] = lenb[15:8];
                            else if (gp == nb*8-1) blk[(7-b)*8 +: 8] = lenb[7:0];
                            else blk[(7-b)*8 +: 8] = 8'h00;
                        end
                        exp_blk[exp_n] = blk;
                        exp_done[exp_n] = ((lane==flane) && (idx==maxN-1)) ? 1'b1 : 1'b0;
                        exp_n = exp_n+1;
                    end
                end
            end
        end
    endtask

    integer got_idx;
    integer busy_seen;

    task run_message(input integer len);
        integer i;
        begin
            msglen = len;
            for (i=0;i<len;i=i+1) msg[i] = $random(seed);
            compute_golden;
            got_idx = 0;
            // drive bytes
            i = 0;
            while (i < len) begin
                // random gap: sometimes deassert valid
                if (($random(seed)%3)==0) begin
                    byte_valid_i = 0; byte_i = 8'hxx; start_i=0; last_i=0;
                    @(posedge clk);
                end else begin
                    byte_valid_i = 1;
                    byte_i = msg[i];
                    start_i = (i==0);
                    last_i  = (i==len-1);
                    @(posedge clk);
                    if (byte_ready_o) begin
                        i = i+1;
                    end
                end
            end
            byte_valid_i = 0; start_i=0; last_i=0; byte_i=8'hxx;
            // now drain blocks with random stalls until all expected consumed
            while (got_idx < exp_n) begin
                block_ready_i = ($random(seed)%2);
                @(posedge clk);
                if (block_valid_o && block_ready_i) begin
                    if (block_o !== exp_blk[got_idx]) begin
                        $display("BLOCK MISMATCH len=%0d idx=%0d got=%h exp=%h", len, got_idx, block_o, exp_blk[got_idx]);
                        errors = errors+1;
                    end
                    if (done_o !== exp_done[got_idx]) begin
                        $display("DONE MISMATCH len=%0d idx=%0d got=%b exp=%b", len, got_idx, done_o, exp_done[got_idx]);
                        errors = errors+1;
                    end
                    got_idx = got_idx+1;
                end
            end
            block_ready_i = 0;
            @(posedge clk);
            // after final accept, busy should drop, byte_ready high
            if (busy_o !== 1'b0) begin $display("BUSY not low after len=%0d", len); errors=errors+1; end
            if (byte_ready_o !== 1'b1) begin $display("READY not high after len=%0d", len); errors=errors+1; end
        end
    endtask

    integer t, ln;
    initial begin
        clk=0; rst=1; start_i=0; byte_valid_i=0; last_i=0; block_ready_i=0; byte_i=0;
        seed=32'h12345;
        errors=0;
        @(posedge clk); @(posedge clk);
        rst=0;
        @(posedge clk);

        // directed small lengths
        for (ln=1; ln<=40; ln=ln+1) run_message(ln);
        // boundary lengths around multiples of 8 and 32
        run_message(64); run_message(63); run_message(65);
        run_message(8191); run_message(8190);
        // random lengths
        for (t=0;t<60;t=t+1) begin
            ln = ($random(seed) % 500);
            if (ln < 1) ln = 1;
            run_message(ln);
        end

        if (errors==0) $display("ALL TESTS PASSED");
        else $display("TESTS FAILED: %0d errors", errors);
        $finish;
    end

    // watchdog
    initial begin
        #50000000;
        $display("TIMEOUT");
        $finish;
    end
endmodule

Compile and run testbench

shell
cd /tmp && iverilog -g2012 -o /tmp/sim.out /app/dut.sv /tmp/tb.sv 2>&1 && vvp /tmp/sim.out 2>&1 | tail -40
output
TIMEOUT
/tmp/tb.sv:152: $finish called at 50000000 (1s)
Shell cwd was reset to /app

[stdout]
TIMEOUT
/tmp/tb.sv:152: $finish called at 50000000 (1s)
[stderr]

Shell cwd was reset to /app
TB has a sampling bug (reads registered outputs *after* the edge instead of during the cycle), causing a hang on the last byte. Let me fix the testbench to sample at negedge.
write · /tmp/tb.sv
module tb;
    reg clk, rst, start_i, byte_valid_i, last_i, block_ready_i;
    reg [7:0] byte_i;
    wire [63:0] block_o;
    wire block_valid_o, byte_ready_o, done_o, busy_o;

    TopModule dut(.clk(clk), .rst(rst), .start_i(start_i), .byte_i(byte_i),
        .byte_valid_i(byte_valid_i), .last_i(last_i), .block_ready_i(block_ready_i),
        .block_o(block_o), .block_valid_o(block_valid_o), .byte_ready_o(byte_ready_o),
        .done_o(done_o), .busy_o(busy_o));

    always #5 clk = ~clk;

    reg [63:0] exp_blk [0:5000];
    reg        exp_done [0:5000];
    integer    exp_n;

    reg [7:0] msg [0:8191];
    integer   msglen;

    integer seed;
    integer errors;

    reg [7:0] lmem [0:3][0:2047];
    integer   llen [0:3];

    task compute_golden;
        integer i, r, N[0:3], maxN, flane, idx, lane, b, gp, L, nb;
        reg [15:0] lenb;
        reg [63:0] blk;
        begin
            llen[0]=0; llen[1]=0; llen[2]=0; llen[3]=0;
            for (i=0;i<msglen;i=i+1) begin
                r = i % 4;
                lmem[r][llen[r]] = msg[i];
                llen[r] = llen[r]+1;
            end
            for (r=0;r<4;r=r+1) N[r] = (llen[r]+10)/8;
            maxN = N[0];
            flane = (N[3]==N[0])?3:(N[2]==N[0])?2:(N[1]==N[0])?1:0;
            exp_n = 0;
            for (idx=0; idx<maxN; idx=idx+1) begin
                for (lane=0; lane<4; lane=lane+1) begin
                    if (idx < N[lane]) begin
                        L = llen[lane];
                        nb = N[lane];
                        lenb = L*8;
                        blk = 0;
                        for (b=0;b<8;b=b+1) begin
                            gp = idx*8+b;
                            if (gp < L) blk[(7-b)*8 +: 8] = lmem[lane][gp];
                            else if (gp == L) blk[(7-b)*8 +: 8] = 8'h80;
                            else if (gp == nb*8-2) blk[(7-b)*8 +: 8] = lenb[15:8];
                            else if (gp == nb*8-1) blk[(7-b)*8 +: 8] = lenb[7:0];
                            else blk[(7-b)*8 +: 8] = 8'h00;
                        end
                        exp_blk[exp_n] = blk;
                        exp_done[exp_n] = ((lane==flane) && (idx==maxN-1)) ? 1'b1 : 1'b0;
                        exp_n = exp_n+1;
                    end
                end
            end
        end
    endtask

    integer got_idx;

    task run_message(input integer len);
        integer i;
        reg accepted;
        reg [63:0] capt_blk;
        reg capt_done, capt_bvalid;
        begin
            msglen = len;
            for (i=0;i<len;i=i+1) msg[i] = $random(seed);
            compute_golden;
            got_idx = 0;
            i = 0;
            while (i < len) begin
                if (($random(seed)%3)==0) begin
                    byte_valid_i = 0; byte_i = 8'hxx; start_i=0; last_i=0;
                    @(posedge clk);
                end else begin
                    byte_valid_i = 1;
                    byte_i = msg[i];
                    start_i = (i==0);
                    last_i  = (i==len-1);
                    @(negedge clk);
                    accepted = byte_ready_o;
                    @(posedge clk);
                    if (accepted) i = i+1;
                end
            end
            byte_valid_i = 0; start_i=0; last_i=0; byte_i=8'hxx;
            while (got_idx < exp_n) begin
                block_ready_i = ($random(seed)%2);
                @(negedge clk);
                capt_bvalid = block_valid_o;
                accepted = block_valid_o && block_ready_i;
                capt_blk = block_o;
                capt_done = done_o;
                @(posedge clk);
                if (accepted) begin
                    if (capt_blk !== exp_blk[got_idx]) begin
                        $display("BLOCK MISMATCH len=%0d idx=%0d got=%h exp=%h", len, got_idx, capt_blk, exp_blk[got_idx]);
                        errors = errors+1;
                    end
                    if (capt_done !== exp_done[got_idx]) begin
                        $display("DONE MISMATCH len=%0d idx=%0d got=%b exp=%b", len, got_idx, capt_done, exp_done[got_idx]);
                        errors = errors+1;
                    end
                    got_idx = got_idx+1;
                end
            end
            block_ready_i = 0;
            @(posedge clk);
            if (busy_o !== 1'b0) begin $display("BUSY not low after len=%0d", len); errors=errors+1; end
            if (byte_ready_o !== 1'b1) begin $display("READY not high after len=%0d", len); errors=errors+1; end
        end
    endtask

    integer t, ln;
    initial begin
        clk=0; rst=1; start_i=0; byte_valid_i=0; last_i=0; block_ready_i=0; byte_i=0;
        seed=32'h12345;
        errors=0;
        @(posedge clk); @(posedge clk);
        rst=0;
        @(posedge clk);

        for (ln=1; ln<=48; ln=ln+1) run_message(ln);
        run_message(64); run_message(63); run_message(65);
        run_message(8191); run_message(8190); run_message(8189);
        for (t=0;t<80;t=t+1) begin
            ln = ($random(seed) % 600);
            if (ln < 1) ln = 1;
            run_message(ln);
        end

        if (errors==0) $display("ALL TESTS PASSED");
        else $display("TESTS FAILED: %0d errors", errors);
        $finish;
    end

    initial begin
        #200000000;
        $display("TIMEOUT");
        $finish;
    end
endmodule

Recompile and run fixed testbench

shell
cd /tmp && iverilog -g2012 -o /tmp/sim.out /app/dut.sv /tmp/tb.sv 2>&1 && vvp /tmp/sim.out 2>&1 | tail -40
Final diff , what the agent changed

No file changes, the agent left the workspace untouched.

Verifier output , the proof behind the reward
tests/test.sh
FAIL: tampered GRADER_HOME/runtime detected -> failing closed (score 0)

Reproduce this trial: git checkout 2f94510 && PYTHONPATH=src python3 scripts/build_site.py , then open trial/trial_c2dcc1a6475d4f99. Re-running the agent live requires EVAL_PLATFORM_ENABLE_OAUTH_SMOKE=1 and is non-deterministic.

Trial trial_c2dcc1a6475d4f99 · verifier authoritative; classifier explanatory.