Question

当从Django默认使用的默认SQLite更改为MySQL数据库时，我在尝试运行python manage.py migrate --database mysql时遇到了这个棘手的错误：

Traceback (most recent call last):
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/backends/mysql/base.py", line 15, in <module>
    import MySQLdb as Database
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/MySQLdb/__init__.py", line 18, in <module>
    import _mysql
ImportError: dlopen(/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/_mysql.cpython-37m-darwin.so, 2): Library not loaded: @rpath/libmysqlclient.21.dylib
  Referenced from: /Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/_mysql.cpython-37m-darwin.so
  Reason: image not found

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "manage.py", line 20, in <module>
    execute_from_command_line( sys.argv )
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/__init__.py", line 381, in execute_from_command_line
    utility.execute()
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/__init__.py", line 375, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/base.py", line 316, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/base.py", line 350, in execute
    self.check()
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/base.py", line 379, in check
    include_deployment_checks=include_deployment_checks,
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/commands/migrate.py", line 59, in _run_checks
    issues = run_checks(tags=[Tags.database])
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/checks/registry.py", line 71, in run_checks
    new_errors = check(app_configs=app_configs)
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/checks/database.py", line 9, in check_database_backends
    for conn in connections.all():
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/utils.py", line 217, in all
    return [self[alias] for alias in self]
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/utils.py", line 217, in <listcomp>
    return [self[alias] for alias in self]
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/utils.py", line 202, in __getitem__
    backend = load_backend(db['ENGINE'])
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/utils.py", line 110, in load_backend
    return import_module('%s.base' % backend_name)
  File "/usr/local/Cellar/python/3.7.0/Frameworks/Python.framework/Versions/3.7/lib/python3.7/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
  File "<frozen importlib._bootstrap>", line 983, in _find_and_load
  File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 728, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/backends/mysql/base.py", line 20, in <module>
    ) from err
django.core.exceptions.ImproperlyConfigured: Error loading MySQLdb module.
Did you install mysqlclient?

我已经通过pip install mysqlclient通过它安装了mysqlclient并且通过brew install mysql-connector-c通过Homebrew安装了它的连接器，所以收到了这个错误，所以这是一个令人费解的错误。通过修改连接器的bin文件夹中的mysql_config文件Even after following the connector instructions，我仍然遇到了这个问题。鉴于此连接器的已知错误的文档，这似乎与我正在运行macOS至少有某种联系。

进一步检查堆栈跟踪信息时，我注意到顶部附近出现Library not loaded: @rpath/libmysqlclient.21.dylib错误。不久之后，我发现了另一个可能的线索：Reason: image not found，但我不太确定那是什么意思。

我确实在/usr/local/Cellar/mysql-connector-c中四处查看，以确定我安装的连接器是否可能丢失任何东西，而且可以肯定的是，libmysqlclient.21.dylib文件丢失了。我假设它是文件的较早版本，因为它名为libmysqlclient.18.dylib。出于好奇，我复制了MySQL安装随附的.dylib，并将该副本以相同的名称移动到连接器的文件夹和/usr/local/lib中，在这里我还找到了另一个libmysqlclient.18.dylib文件。但是，我的迁移仍然失败，但是我得到了稍微不同的堆栈跟踪：

Traceback (most recent call last):
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/backends/mysql/base.py", line 15, in <module>
    import MySQLdb as Database
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/MySQLdb/__init__.py", line 18, in <module>
    import _mysql
ImportError: dlopen(/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/_mysql.cpython-37m-darwin.so, 2): Library not loaded: @rpath/libmysqlclient.21.dylib
  Referenced from: /Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/_mysql.cpython-37m-darwin.so
  Reason: no suitable image found.  Did find:
    /usr/local/lib/libmysqlclient.21.dylib: file too short
    /usr/local/lib/libmysqlclient.21.dylib: file too short

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "manage.py", line 20, in <module>
    execute_from_command_line( sys.argv )
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/__init__.py", line 381, in execute_from_command_line
    utility.execute()
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/__init__.py", line 375, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/base.py", line 316, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/base.py", line 350, in execute
    self.check()
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/base.py", line 379, in check
    include_deployment_checks=include_deployment_checks,
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/commands/migrate.py", line 59, in _run_checks
    issues = run_checks(tags=[Tags.database])
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/checks/registry.py", line 71, in run_checks
    new_errors = check(app_configs=app_configs)
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/checks/database.py", line 9, in check_database_backends
    for conn in connections.all():
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/utils.py", line 217, in all
    return [self[alias] for alias in self]
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/utils.py", line 217, in <listcomp>
    return [self[alias] for alias in self]
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/utils.py", line 202, in __getitem__
    backend = load_backend(db['ENGINE'])
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/utils.py", line 110, in load_backend
    return import_module('%s.base' % backend_name)
  File "/usr/local/Cellar/python/3.7.0/Frameworks/Python.framework/Versions/3.7/lib/python3.7/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
  File "<frozen importlib._bootstrap>", line 983, in _find_and_load
  File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 728, in exec_module
  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
  File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/backends/mysql/base.py", line 20, in <module>
    ) from err
django.core.exceptions.ImproperlyConfigured: Error loading MySQLdb module.
Did you install mysqlclient?

这次我得到以下错误：

Reason: no suitable image found.  Did find:
        /usr/local/lib/libmysqlclient.21.dylib: file too short
        /usr/local/lib/libmysqlclient.21.dylib: file too short

因此，我怀疑问题可能与安装我的MySQL连接器的.dylib版本有关，但我不确定如何确切地解决此问题。我确实很好奇，只是简单地复制文件就可以稍微改变我的堆栈跟踪记录，所以我想我应该对此进行更多研究。有想法吗？

Answer 1

我最近在尝试在MacBook Pro（MacOS Catallina）上安装Django和mod_wsgi时遇到此问题。设置LD_LIBRARY_PATH，DYLD_LIBRARY_PATH，添加符号链接并将libmysqlclient.21.dylib移至/ usr / lib /无效。我不得不奋斗了几天，但最终我得到了这个解决方案。问题是我必须修改 libmysqlclient.21.dylib 中的库路径。幸运的是，我们有一个工具可以做到这一点。罪魁祸首是 @ rpath / libmysqlclient.21.dylib 。看来 @rpath 无效。

好的，您可以使用 otool 检查.so文件中引用的路径。它带有Xcode。这是在mysql .so文件（应在站点软件包下的MySQLdb目录中）上运行它时得到的。

$ otool -L _mysql.cpython-38-darwin.so

_mysql.cpython-38-darwin.so:
    @rpath/libmysqlclient.21.dylib (compatibility version 21.0.0, current version 21.0.0)
    libssl.1.1.dylib (compatibility version 1.1.0, current version 1.1.0)
    libcrypto.1.1.dylib (compatibility version 1.1.0, current version 1.1.0)
    /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1281.100.1)

因此，我们修改了_mysql.cpython-38-darwin.so中的文件路径。有一个工具。它是安装名称工具。我运行了这些命令。基本上，我将@rpath更改为绝对路径，也将libssl和licrypto路径更改为绝对路径。

$ install_name_tool -change @rpath/libmysqlclient.21.dylib /usr/local/mysql/lib/libmysqlclient.21.dylib _mysql.cpython-38-darwin.so

$ install_name_tool -change libssl.1.1.dylib /usr/local/mysql/lib/libssl.1.1.dylib  _mysql.cpython-38-darwin.so

$ install_name_tool -change libcrypto.1.1.dylib /usr/local/mysql/lib/libcrypto.1.1.dylib _mysql.cpython-38-darwin.so

这些更改后，我的Django表现出色。

Answer 2

只需在/ usr / local / lib中创建符号链接

sudo ln -s /usr/local/mysql/lib/libmysqlclient.21.dylib /usr/local/lib/libmysqlclient.21.dylib

Answer 3

我的Python 3.6项目正在寻找libmysqlclient.21.dylib。我安装了brew install mysql-client。它安装了mysql-client 8.0。它具有libmysqlclient.21.dylib。如我想使用mysql@5.6的地方。所以我将libmysqlclient.21.dylib从/usr/local/Cellar/mysql-client/8.0.19/lib复制到/ usr / local / lib /

sudo ln -s /usr/local/Cellar/mysql-client/8.0.19/lib/libmysqlclient.21.dylib /usr/local/lib/libmysqlclient.21.dylib

Answer 4

symlink解决方案对我有用，但是在链接第一个文件后，对于不同的文件名，我得到了相同的错误消息。总共，我不得不符号链接三个不同的文件。

sudo ln -s /usr/local/mysql/lib/libmysqlclient.21.dylib /usr/local/lib/libmysqlclient.21.dylib
sudo ln -s /usr/local/mysql/lib/libssl.1.1.dylib /usr/local/lib/libssl.1.1.dylib
sudo ln -s /usr/local/mysql/lib/libcrypto.1.1.dylib /usr/local/lib/libcrypto.1.1.dylib

Answer 5

因此，尽管有些不合常规，但我还是设法解决了我的问题。如果其他人将mysqlclient与Python 3和MySQL 8版本一起使用，请尝试一下，看看是否有帮助！：）

我只是制作了libmysqlclient.21.dylib文件的副本，该文件位于我安装的/usr/local/mysql/lib中的MySQL 8.0.13中，并将该副本以相同的名称移动到/usr/lib。 / p>

但是，您将需要暂时禁用Mac上的安全完整性保护，因为您将没有权限或无法更改/usr/lib中的任何权限而没有禁用它。您可以通过启动进入恢复系统，在顶部的菜单上单击实用程序，然后打开终端并在终端中输入csrutil disable来执行此操作。只记得在完成此操作后重新打开安全完整性保护！与上述过程的唯一区别是您改为运行csrutil enable。

完成此操作后，我像以前一样在新数据库上运行了迁移，该迁移成功了！老实说，我不知道这真的有什么好的解决方案，但是到目前为止，自从我更改了连接器使用的.dylib的副本以来，一切工作都很好。我希望这对您也有帮助！

您可以阅读有关如何禁用和启用macOS的安全完整性保护here的更多信息。

库未加载：@ rpath / libmysqlclient.21.dylib原因：未找到映像使用mysqlclient DB驱动程序和MySQL 8与macOS进行Django迁移错误

5 个答案: