conda create虚拟环境报错

报错内容：

Collecting package metadata (current_repodata.json): failed

# >>>>>>>>>>>>>>>>>>>>>> ERROR REPORT <<<<<<<<<<<<<<<<<<<<<<

    Traceback (most recent call last):
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/core/subdir_data.py", line 719, in fetch_repodata_remote_request
        resp.raise_for_status()
      File "/usr/lib/python3/dist-packages/requests/models.py", line 940, in raise_for_status
        raise HTTPError(http_error_msg, response=self)
    requests.exceptions.HTTPError: 404 Client Error: Not Found for url: https://mirrors.tuna.tsinghua.edu.cn/anaconda/pkgs/free/noarch/current_repodata.json
    
    During handling of the above exception, another exception occurred:
    
    Traceback (most recent call last):
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/exceptions.py", line 1125, in __call__
        return func(*args, **kwargs)
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/cli/main.py", line 86, in main_subshell
        exit_code = do_call(args, p)
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/cli/conda_argparse.py", line 93, in do_call
        return getattr(module, func_name)(args, parser)
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/notices/core.py", line 72, in wrapper
        return_value = func(*args, **kwargs)
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/cli/main_create.py", line 43, in execute
        install(args, parser, 'create')
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/cli/install.py", line 260, in install
        should_retry_solve=(_should_retry_unfrozen or repodata_fn != repodata_fns[-1]),
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/core/solve.py", line 155, in solve_for_transaction
        should_retry_solve)
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/core/solve.py", line 196, in solve_for_diff
        force_remove, should_retry_solve)
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/core/solve.py", line 300, in solve_final_state
        ssc = self._collect_all_metadata(ssc)
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/common/io.py", line 86, in decorated
        return f(*args, **kwds)
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/core/solve.py", line 463, in _collect_all_metadata
        index, r = self._prepare(prepared_specs)
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/core/solve.py", line 1058, in _prepare
        self.subdirs, prepared_specs, self._repodata_fn)
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/core/index.py", line 298, in get_reduced_index
        repodata_fn=repodata_fn)
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/core/subdir_data.py", line 152, in query_all
        result = tuple(concat(executor.map(subdir_query, channel_urls)))
      File "/home/tuolong/anaconda3/lib/python3.7/concurrent/futures/_base.py", line 586, in result_iterator
        yield fs.pop().result()
      File "/home/tuolong/anaconda3/lib/python3.7/concurrent/futures/_base.py", line 425, in result
        return self.__get_result()
      File "/home/tuolong/anaconda3/lib/python3.7/concurrent/futures/_base.py", line 384, in __get_result
        raise self._exception
      File "/home/tuolong/anaconda3/lib/python3.7/concurrent/futures/thread.py", line 57, in run
        result = self.fn(*self.args, **self.kwargs)
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/core/subdir_data.py", line 145, in 
        package_ref_or_match_spec))
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/core/subdir_data.py", line 157, in query
        self.load()
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/core/subdir_data.py", line 222, in load
        _internal_state = self._load()
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/core/subdir_data.py", line 391, in _load
        repodata_fn=self.repodata_fn)
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/core/subdir_data.py", line 778, in fetch_repodata_remote_request
        response=e.response,
      File "/home/tuolong/anaconda3/lib/python3.7/site-packages/conda/exceptions.py", line 460, in __init__
        body = response.json()
      File "/usr/lib/python3/dist-packages/requests/models.py", line 897, in json
        return complexjson.loads(self.text, **kwargs)
      File "/usr/lib/python3/dist-packages/simplejson/__init__.py", line 518, in loads
        return _default_decoder.decode(s)
      File "/usr/lib/python3/dist-packages/simplejson/decoder.py", line 370, in decode
        obj, end = self.raw_decode(s)
      File "/usr/lib/python3/dist-packages/simplejson/decoder.py", line 400, in raw_decode
        return self.scan_once(s, idx=_w(s, idx).end())
      File "/usr/lib/python3/dist-packages/simplejson/scanner.py", line 79, in scan_once
        return _scan_once(string, idx)
      File "/usr/lib/python3/dist-packages/simplejson/scanner.py", line 70, in _scan_once
        raise JSONDecodeError(errmsg, string, idx)
    simplejson.errors.JSONDecodeError: Expecting value: line 1 column 1 (char 0)

`$ /home/tuolong/anaconda3/bin/conda create -n yolov7 python=3.7`

  environment variables:
                 CIO_TEST=
        CMAKE_PREFIX_PATH=/opt/ros/noetic
        CONDA_DEFAULT_ENV=base
                CONDA_EXE=/home/tuolong/anaconda3/bin/conda
             CONDA_PREFIX=/home/tuolong/anaconda3
    CONDA_PROMPT_MODIFIER=(base)
         CONDA_PYTHON_EXE=/home/tuolong/anaconda3/bin/python
               CONDA_ROOT=/home/tuolong/anaconda3
              CONDA_SHLVL=1
           CURL_CA_BUNDLE=
          LD_LIBRARY_PATH=/opt/ros/noetic/lib:/home/tuolong/freenect2/lib:/usr/local/cuda-11.2/l
                          ib64
                     PATH=/home/tuolong/anaconda3/bin:/home/tuolong/anaconda3/bin:/home/tuolong/
                          anaconda3/condabin:/opt/ros/noetic/bin:/home/tuolong/freenect2/lib/cma
                          ke/freenect2:/usr/local/cuda-11.2/bin:/home/tuolong/anaconda3/bin:/hom
                          e/tuolong/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin
                          :/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
          PKG_CONFIG_PATH=/opt/ros/noetic/lib/pkgconfig
               PYTHONPATH=/opt/ros/noetic/lib/python3/dist-packages:/usr/lib/python3/dist-
                          packages
       REQUESTS_CA_BUNDLE=
         ROS_PACKAGE_PATH=/opt/ros/noetic/share
            SSL_CERT_FILE=
               WINDOWPATH=2

     active environment : base
    active env location : /home/tuolong/anaconda3
            shell level : 1
       user config file : /home/tuolong/.condarc
 populated config files : /home/tuolong/.condarc
          conda version : 4.14.0
    conda-build version : not installed
         python version : 3.7.0.final.0
       virtual packages : __cuda=11.6=0
                          __linux=5.15.0=0
                          __glibc=2.31=0
                          __unix=0=0
                          __archspec=1=x86_64
       base environment : /home/tuolong/anaconda3  (writable)
      conda av data dir : /home/tuolong/anaconda3/etc/conda
  conda av metadata url : None
           channel URLs : https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/conda-forge/linux-64
                          https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud/conda-forge/noarch
                          https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud//pytorch/linux-64
                          https://mirrors.tuna.tsinghua.edu.cn/anaconda/cloud//pytorch/noarch
                          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://repo.anaconda.com/pkgs/main/linux-64
                          https://repo.anaconda.com/pkgs/main/noarch
                          https://repo.anaconda.com/pkgs/r/linux-64
                          https://repo.anaconda.com/pkgs/r/noarch
          package cache : /home/tuolong/anaconda3/pkgs
                          /home/tuolong/.conda/pkgs
       envs directories : /home/tuolong/anaconda3/envs
                          /home/tuolong/.conda/envs
               platform : linux-64
             user-agent : conda/4.14.0 requests/2.22.0 CPython/3.7.0 Linux/5.15.0-69-generic ubuntu/20.04.6 glibc/2.31
                UID:GID : 1000:1000
             netrc file : None
           offline mode : False


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报错原因：找不到清华源镜像

解决办法

#step1: 删除原有镜像
(base) tuolong@tuolong-20:~/anaconda3/envs$ conda config --remove-key channels
#step2: 添加默认镜像
(base) tuolong@tuolong-20:~/anaconda3/envs$ conda config --append channels conda-forge --append channels bioconda --append channels defaults

参考：

CondaHTTPError: HTTP 404 NOT FOUND for url https://pypi.tuna.tsinghua.edu.cn/simple/ 错误