Mobilenetv3 decoder(list of tensors input) export issue

Hello,

There was an error: "RuntimeError: output 1 (3[ CPULongType{} ]) of traced region did not have observable data dependence with trace inputs; this probably indicates your program cannot be understood by the tracer." encountered when I was exporting my mobilenetv3 decoder to onnx.

I suspect it is due to my input type since it contains multiple scales of image(list of tensors).

Here is my decoder code snippet:

class MobilenetV3DecoderV1(nn.Module):
    def __init__(
        self,
        num_ch_enc,
        scales=range(4),
        num_output_channels=1,
        use_skips=True,
        mode="mobilenet_v3_small",
    ) -> None:
        super().__init__()

        self.num_output_channels = num_output_channels
        self.use_skips = use_skips
        self.upsample_mode = "nearest"
        self.scales = scales

        self.num_ch_enc = num_ch_enc
        if mode == "mobilenet_v3_large" or mode == "mobilenet_v3_large_quantize":
            self.num_ch_dec = np.array([16, 32, 64, 128, 256])
        elif mode == "mobilenet_v3_small":
            self.num_ch_dec = np.array([4, 12, 20, 40, 80])

        # decoder
        self.convs = OrderedDict()
        self.num_of_scales = len(scales)
        for i in range(self.num_of_scales, -1, -1):
            # upconv_0
            num_ch_in = self.num_ch_enc[-1] if i == self.num_of_scales else self.num_ch_dec[i + 1]
            num_ch_out = self.num_ch_dec[i]
            self.convs[("upconv", i, 0)] = ConvBlock(num_ch_in, num_ch_out)

            # upconv_1
            num_ch_in = self.num_ch_dec[i]
            if self.use_skips and i > 0:
                num_ch_in += self.num_ch_enc[i - 1]
            num_ch_out = self.num_ch_dec[i]
            self.convs[("upconv", i, 1)] = ConvBlock(num_ch_in, num_ch_out)

        for s in self.scales:
            self.convs[("dispconv", s)] = Conv3x3(
                self.num_ch_dec[s], self.num_output_channels
            )

        self.decoder = nn.ModuleList(list(self.convs.values()))
        self.sigmoid = nn.Sigmoid()

    def forward(self, input_features):
        self.outputs = {}
        # decoder
        x = input_features[-1]
        for i in range(self.num_of_scales, -1, -1):
            x = self.convs[("upconv", i, 0)](x)
            # if i != 0:
            #     x = self.convs[("attentionconv", i)](x, [input_features[i-1]])
            # else:
            x = [upsample(x)]
            if self.use_skips and i > 0:
                x += [input_features[i - 1]]
            x = torch.cat(x, 1)
            x = self.convs[("upconv", i, 1)](x)
            if i in self.scales:
                self.outputs[("disp", i)] = self.sigmoid(self.convs[("dispconv", i)](x))
        return self.outputs

Is there a way can export it to onnx correctly?
Thanks in advance!