When I was runing the code，I met the following problem.Can you help me?

DATA_ROOT=./datasets/experiment name=SAGAN which_direction=AtoB phase=test th test.lua
{
input_nc : 3
results_dir : "./results/"
Size : 512
batchSize : 1
phase : "test"
fineSize : 512
aspect_ratio : 1
how_many : "all"
gpu : 1
nThreads : 1
DATA_ROOT : "./datasets/experiment"
serial_batch_iter : 1
preprocess : "regular"
norm : "batch"
which_epoch : "latest"
name : "SAGAN"
cudnn : 1
serial_batches : 1
flip : 0
output_nc : 3
which_direction : "AtoB"
checkpoints_dir : "/home/angus/Documents/project/Medical_image/SAGAN/checkpoints"
display_id : 200
display : 0
}
Random Seed: 7774
#threads...1
Starting donkey with id: 1 seed: 7775
table: 0x41c20428
./datasets/experiment
trainCache /home/angus/Documents/rfid-project/Medical_image/SAGAN/cache/_home_angus_Documents_project_Medical_image_SAGAN_datasets_experiment_test_trainCache.t7
Creating train metadata
serial batch:, 1
table: 0x41dc8138
running "find" on each class directory, and concatenate all those filenames into a single file containing all image paths for a given class
now combine all the files to a single large file
load the large concatenated list of sample paths to self.imagePath
cmd..wc -L '/tmp/lua_RsZajh' |cut -f1 -d' '
64 samples found..... 0/64 .....................] ETA: 0ms | Step: 0ms
Updating classList and imageClass appropriately
[=================== 1/1 =====================>] Tot: 0ms | Step: 0ms
Cleaning up temporary files
Dataset Size: 64
checkpoints_dir /home/angus/Documents/project/Medical_image/SAGAN/checkpoints
/home/angus/torch/install/bin/luajit: /home/angus/torch/install/share/lua/5.1/threads/threads.lua:315: /home/angus/torch/install/share/lua/5.1/threads/threads.lua:183: [thread 1 callback] /home/angus/torch/install/share/lua/5.1/dok/inline.lua:738: <image.scale> could not find valid dest size
stack traceback:
[C]: in function 'error'
/home/angus/torch/install/share/lua/5.1/dok/inline.lua:738: in function 'error'
/home/angus/torch/install/share/lua/5.1/image/init.lua:718: in function 'scale'
.../project/Medical_image/SAGAN/data/donkey_folder.lua:40: in function 'preprocessAandB'
.../project/Medical_image/SAGAN/data/donkey_folder.lua:256: in function 'sampleHookTrain'
...uments/project/Medical_image/SAGAN/data/dataset.lua:342: in function 'getByClass'
...uments/project/Medical_image/SAGAN/data/dataset.lua:375: in function <...uments/project/Medical_image/SAGAN/data/dataset.lua:367>
[C]: in function 'xpcall'
/home/angus/torch/install/share/lua/5.1/threads/threads.lua:234: in function 'callback'
/home/angus/torch/install/share/lua/5.1/threads/queue.lua:65: in function </home/angus/torch/install/share/lua/5.1/threads/queue.lua:41>
[C]: in function 'pcall'
/home/angus/torch/install/share/lua/5.1/threads/queue.lua:40: in function 'dojob'
[string " local Queue = require 'threads.queue'..."]:15: in main chunk