The following NEW packages will be INSTALLED:     bcftools:  1.9-h4da6232_0        https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/bioconda        deeptools: 3.1.2-py27h470a237_0  https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/bioconda        htslib:    1.9-hc238db4_4        https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/bioconda        plotly:    3.2.1-py_0            https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/conda-forge     py2bit:    0.3.0-py27_1          https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/bioconda        pybigwig:  0.3.11-py27he7a497f_2 https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/bioconda        pysam:     0.15.1-py27h0380709_0 https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/bioconda        retrying:  1.3.3-py_2            https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/conda-forge Proceed ([y]/n)? y Preparing transaction: done Verifying transaction: done Executing transaction: failed ERROR conda.core.link:_execute(502): An error occurred while installing package 'https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/bioconda::pybigwig-0.3.11-py27he7a497f_2'. CondaError: Cannot link a source that does not exist. /home/sfh123/anaconda2/.condatmp/0f2ecb85-52a0-416d-a820-3b3f68a748cc Running `conda clean --packages` may resolve your problem. Attempting to roll back. Rolling back transaction: done CondaError: Cannot link a source that does not exist. /home/sfh123/anaconda2/.condatmp/0f2ecb85-52a0-416d-a820-3b3f68a748cc Running `conda clean --packages` may resolve your problem.       请问是网络问题吗？还是需要卸载一些东西呢？