莫名奇妙出现这个问题：

# >>>>>>>>>>>>>>>>>>>>>> ERROR REPORT <<<<<<<<<<<<<<<<<<<<<< Traceback (most recent call last): File "/root/anaconda3/lib/python3.7/site-packages/conda/exceptions.py", line 1079, in __call__ return func(*args, **kwargs) File "/root/anaconda3/lib/python3.7/site-packages/conda/cli/main.py", line 84, in _main exit_code = do_call(args, p) File "/root/anaconda3/lib/python3.7/site-packages/conda/cli/conda_argparse.py", line 82, in do_call return getattr(module, func_name)(args, parser) File "/root/anaconda3/lib/python3.7/site-packages/conda/cli/main_update.py", line 20, in execute install(args, parser, 'update') File "/root/anaconda3/lib/python3.7/site-packages/conda/cli/install.py", line 116, in install if context.use_only_tar_bz2: File "/root/anaconda3/lib/python3.7/site-packages/conda/base/context.py", line 710, in use_only_tar_bz2 import conda_package_handling.api File "/root/anaconda3/lib/python3.7/site-packages/conda_package_handling/api.py", line 140, in <module> tmpdir_root=_tempfile.gettempdir(), processes=None): File "/root/anaconda3/lib/python3.7/tempfile.py", line 294, in gettempdir tempdir = _get_default_tempdir() File "/root/anaconda3/lib/python3.7/tempfile.py", line 229, in _get_default_tempdir dirlist) FileNotFoundError: [Errno 2] No usable temporary directory found in ['/tmp', '/var/tmp', '/usr/tmp', '/'] `$ /root/anaconda3/bin/conda update -n base -c defaults conda` environment variables: CIO_TEST=<not set> CONDA_DEFAULT_ENV=FairMOT CONDA_EXE=/root/anaconda3/bin/conda CONDA_PREFIX=/root/anaconda3/envs/FairMOT CONDA_PREFIX_1=/root/anaconda3 CONDA_PROMPT_MODIFIER=(FairMOT) CONDA_PYTHON_EXE=/root/anaconda3/bin/python CONDA_ROOT=/root/anaconda3 CONDA_SHLVL=2 LD_LIBRARY_PATH=/usr/local/nvidia/lib:/usr/local/nvidia/lib64 LIBRARY_PATH=/usr/local/cuda/lib64/stubs PATH=/root/anaconda3/bin:/root/anaconda3/envs/FairMOT/bin:/root/anaconda3/c ondabin:/usr/local/nvidia/bin:/usr/local/cuda/bin:/usr/local/sbin:/usr /local/bin:/usr/sbin:/usr/bin:/sbin:/bin REQUESTS_CA_BUNDLE=<not set> SSL_CERT_FILE=<not set> active environment : FairMOT active env location : /root/anaconda3/envs/FairMOT shell level : 2 user config file : /root/.condarc populated config files : /root/.condarc conda version : 4.8.3 conda-build version : 3.18.8 python version : 3.7.3.final.0 virtual packages : __cuda=10.2 __glibc=2.23 base environment : /root/anaconda3 (writable) channel URLs : https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main/linux-64 https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/main/noarch https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/free/linux-64 https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/free/noarch https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/r/linux-64 https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/r/noarch https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/pro/linux-64 https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/pro/noarch https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/msys2/linux-64 https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/msys2/noarch package cache : /root/anaconda3/pkgs /root/.conda/pkgs envs directories : /root/anaconda3/envs /root/.conda/envs platform : linux-64 user-agent : conda/4.8.3 requests/2.22.0 CPython/3.7.3 Linux/3.10.0-957.el7.x86_64 ubuntu/16.04.6 glibc/2.23 UID:GID : 0:0 netrc file : None offline mode : False An unexpected error has occurred. Conda has prepared the above report. If submitted, this report will be used by core maintainers to improve future releases of conda. Would you like conda to send this report to the core maintainers?

LZ的解决方法：

conda clean -i

然后就可以了。。。也不知道具体是啥问题，但就是解决了