创建/更新mamba环境时遇UTF-8解码错误，无权限重装求解决

问题情况 #

使用mamba创建或更新环境时触发UTF-8解码错误，报错指向缓存相关操作。尝试执行mamba clean --all清理缓存时，同样触发该错误。无机器权限重装mamba，GitHub上相关conda问题未得到有效解答，以下是报错堆栈及mamba info输出，寻求可行解决办法。

报错堆栈 #

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

Traceback (most recent call last):
  File "/path/to/mamba/lib/python3.10/site-packages/conda/exceptions.py", line 1124, in __call__
    return func(*args, **kwargs)
  File "/path/to/mamba/lib/python3.10/site-packages/conda_env/cli/main.py", line 78, in do_call
    exit_code = getattr(module, func_name)(args, parser)
  File "/path/to/mamba/lib/python3.10/site-packages/conda/notices/core.py", line 109, in wrapper
    return func(*args, **kwargs)
  File "/path/to/mamba/lib/python3.10/site-packages/conda_env/cli/main_create.py", line 154, in execute
    result[installer_type] = installer.install(prefix, pkg_specs, args, env)
  File "/path/to/mamba/lib/python3.10/site-packages/mamba/mamba_env.py", line 173, in mamba_install
    handle_txn(conda_transaction, prefix, args, True)
  File "/path/to/mamba/lib/python3.10/site-packages/mamba/linking.py", line 38, in handle_txn
    unlink_link_transaction.download_and_extract()
  File "/path/to/mamba/lib/python3.10/site-packages/conda/core/link.py", line 205, in download_and_extract
    self._pfe.execute()
  File "/path/to/mamba/lib/python3.10/site-packages/conda/core/package_cache_data.py", line 707, in execute
    self.prepare()
  File "/path/to/mamba/lib/python3.10/site-packages/conda/common/io.py", line 84, in decorated
    return f(*args, **kwds)
  File "/path/to/mamba/lib/python3.10/site-packages/conda/core/package_cache_data.py", line 686, in prepare
    self.paired_actions.update(
  File "/path/to/mamba/lib/python3.10/site-packages/conda/core/package_cache_data.py", line 687, in <genexpr>
    (prec, self.make_actions_for_record(prec)) for prec in self.link_precs
  File "/path/to/mamba/lib/python3.10/site-packages/conda/core/package_cache_data.py", line 554, in make_actions_for_record
    extracted_pcrec = next(
  File "/path/to/mamba/lib/python3.10/site-packages/conda/core/package_cache_data.py", line 555, in <genexpr>
    (
  File "/path/to/mamba/lib/python3.10/site-packages/conda/core/package_cache_data.py", line 558, in <genexpr>
    PackageCacheData(pkgs_dir).query(pref_or_spec)
  File "/path/to/mamba/lib/python3.10/site-packages/conda/core/package_cache_data.py", line 82, in __call__
    package_cache_instance = super().__call__(pkgs_dir)
  File "/path/to/mamba/lib/python3.10/site-packages/conda/core/package_cache_data.py", line 95, in __init__
    self._urls_data = UrlsData(pkgs_dir)
  File "/path/to/mamba/lib/python3.10/site-packages/conda/core/package_cache_data.py", line 489, in __init__
    self._urls_data = [line.strip().decode("utf-8") for line in fh]
  File "/path/to/mamba/lib/python3.10/site-packages/conda/core/package_cache_data.py", line 489, in <listcomp>
    self._urls_data = [line.strip().decode("utf-8") for line in fh]
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xb3 in position 1: invalid start byte

`$ /path/to/mamba/bin/mamba create -n <NAME> -f <FILE>`

mamba info输出 #

active environment : base
    active env location : <PRIVATE>/mamba
            shell level : 3
       user config file : <PRIVATE>/.condarc
 populated config files : <PRIVATE>/.condarc
          conda version : 23.1.0
    conda-build version : not installed
         python version : 3.10.9.final.0
       virtual packages : __archspec=1=x86_64
                          __glibc=2.17=0
                          __linux=3.10.0=0
                          __unix=0=0
       base environment : <PRIVATE>/mamba  (read only)
      conda av data dir : <PRIVATE>/mamba/etc/conda
  conda av metadata url : None
           channel URLs : <PRIVATE>
                          <PRIVATE>
                          <PRIVATE>
                          <PRIVATE>
                          <PRIVATE>
                          <PRIVATE>
                          <PRIVATE>
                          <PRIVATE>
                          <PRIVATE>
                          <PRIVATE>
          package cache : <PRIVATE>/.conda/pkgs
                          <PRIVATE>/miniconda3/pkgs
       envs directories : <PRIVATE>/.conda/envs
                          <PRIVATE>/conda_envs
               platform : linux-64
             user-agent : conda/23.1.0 requests/2.28.2 CPython/3.10.9 Linux/3.10.0-1160.95.1.el7.x86_64 rhel/7.9 glibc/2.17
                UID:GID : 688555:688555
             netrc file : <PRIVATE>/.netrc
           offline mode : False

可行解决办法 #

• 手动删除缓存中的.urls文件：从报错可知是缓存目录下的URL记录文件编码异常。找到mamba info中列出的两个package cache目录（<PRIVATE>/.conda/pkgs和<PRIVATE>/miniconda3/pkgs），进入每个目录删除所有.urls后缀的文件，这些文件是下载URL的缓存，删除后mamba会自动重新生成。
• 强制UTF-8编码环境变量：执行mamba命令前设置环境变量，强制Python用UTF-8处理编码，示例命令：

  PYTHONUTF8=1 mamba create -n <NAME> -f <FILE>
  

  或者：

  LC_ALL=en_US.UTF-8 mamba create -n <NAME> -f <FILE>
  

• 指定新的缓存目录：创建一个全新的缓存目录，执行命令时绕过原有异常缓存，示例：

  mkdir -p ~/new_conda_cache
  mamba create -n <NAME> -f <FILE> --pkgs-dir ~/new_conda_cache
  

• 检查.condarc配置：查看用户配置文件<PRIVATE>/.condarc，确认是否存在异常的缓存路径配置或非UTF-8编码相关设置，如有则调整对应项。

内容的提问来源于stack exchange，提问作者leqo