将DYLD_LIBRARY_PATH添加到bashrc时，Anaconda停止工作

我在macOS Mojave 10.14.5上使用Anaconda Navigator 1.9.7版本。当我将以下命令添加到.bashrc时，我发现大多数anaconda-navigator，pip，...命令停止工作。

export DYLD_LIBRARY_PATH=/opt/x11/lib/:/opt/local/lib/libgcc/:/opt/local/lib/gcc47/:$DYLD_LIBRARY_PATH

对于pip命令，出现以下错误：

Traceback (most recent call last):
  File "/Users/ahmedlasheen/anaconda3/bin/pip", line 7, in <module>
    from pip._internal import main
  File "/Users/ahmedlasheen/anaconda3/lib/python3.7/site-packages/pip/_internal/__init__.py", line 40, in <module>
    from pip._internal.cli.autocompletion import autocomplete
  File "/Users/ahmedlasheen/anaconda3/lib/python3.7/site-packages/pip/_internal/cli/autocompletion.py", line 8, in <module>
    from pip._internal.cli.main_parser import create_main_parser
  File "/Users/ahmedlasheen/anaconda3/lib/python3.7/site-packages/pip/_internal/cli/main_parser.py", line 12, in <module>
    from pip._internal.commands import (
  File "/Users/ahmedlasheen/anaconda3/lib/python3.7/site-packages/pip/_internal/commands/__init__.py", line 6, in <module>
    from pip._internal.commands.completion import CompletionCommand
  File "/Users/ahmedlasheen/anaconda3/lib/python3.7/site-packages/pip/_internal/commands/completion.py", line 6, in <module>
    from pip._internal.cli.base_command import Command
  File "/Users/ahmedlasheen/anaconda3/lib/python3.7/site-packages/pip/_internal/cli/base_command.py", line 20, in <module>
    from pip._internal.download import PipSession
  File "/Users/ahmedlasheen/anaconda3/lib/python3.7/site-packages/pip/_internal/download.py", line 15, in <module>
    from pip._vendor import requests, six, urllib3
  File "/Users/ahmedlasheen/anaconda3/lib/python3.7/site-packages/pip/_vendor/requests/__init__.py", line 114, in <module>
    from . import utils
  File "/Users/ahmedlasheen/anaconda3/lib/python3.7/site-packages/pip/_vendor/requests/utils.py", line 26, in <module>
    from ._internal_utils import to_native_string
  File "/Users/ahmedlasheen/anaconda3/lib/python3.7/site-packages/pip/_vendor/requests/_internal_utils.py", line 11, in <module>
    from .compat import is_py2, builtin_str, str
  File "/Users/ahmedlasheen/anaconda3/lib/python3.7/site-packages/pip/_vendor/requests/compat.py", line 62, in <module>
    from urllib.request import parse_http_list, getproxies, proxy_bypass, proxy_bypass_environment, getproxies_environment
  File "/Users/ahmedlasheen/anaconda3/lib/python3.7/urllib/request.py", line 2583, in <module>
    from _scproxy import _get_proxy_settings, _get_proxies
ImportError: dlopen(/Users/ahmedlasheen/anaconda3/lib/python3.7/lib-dynload/_scproxy.cpython-37m-darwin.so, 2): Symbol not found: __cg_png_create_info_struct
  Referenced from: /System/Library/Frameworks/ImageIO.framework/Versions/A/ImageIO
  Expected in: /opt/x11/lib//libPng.dylib
 in /System/Library/Frameworks/ImageIO.framework/Versions/A/ImageIO

该文件/opt/x11/lib//libPng.dylib确实存在。