How to use VOCSegmentation from torchvision?

I have downloaded the VOC2012 dataset and want to use VOCSegmentation for my dataloader, but what ever I do I get the error RuntimeError: Dataset not found or corrupted. You can use download=True to download it .

my dataset looks like this:

/VOCdevkit
└── VOC2012
    ├── Annotations
    ├── ImageSets
    │   └── Segmentation
    ├── JPEGImages
    ├── SegmentationObject
    └── SegmentationClass

can someone tell me how should I set us the VOCSegmentation inputs? I have it like this but it is not working.

dataset = torchvision.datasets.VOCSegmentation(root='/path/VOCdevkit/', year='2012', image_set='trainval', download=False)

the complete error that I am getting is:

~/anaconda3/envs/pytorch/lib/python3.6/site-packages/torchvision/datasets/voc.py in __init__(self, root, year, image_set, download, transform, target_transform, transforms)
    103         if not os.path.isdir(voc_root):
    104             raise RuntimeError('Dataset not found or corrupted.' +
--> 105                                ' You can use download=True to download it')
    106 
    107         splits_dir = os.path.join(voc_root, 'ImageSets/Segmentation')

RuntimeError: Dataset not found or corrupted. You can use download=True to download it

solution is here