库未加载：@rpath/libmysqlclient.21.dylib 原因：找不到图像 使用mysqlclient DB驱动程序和MySQL 8在macOS上使用Django迁移时出现错误

Question

当我试图从Django默认使用的SQLite数据库更改为MySQL数据库时，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安装了mysqlclient，并通过Homebrew使用brew install mysql-connector-c安装了它的连接器，但仍然收到了这个错误。即使按照连接器说明修改了连接器bin文件夹中的mysql_config文件，我仍然遇到了这个问题。鉴于这个连接器已知的bug文档，这似乎与我正在运行的macOS有关。

进一步检查我的堆栈跟踪后，我注意到顶部出现了Library not loaded: @rpath/libmysqlclient.21.dylib错误。紧接着是另一个可能的线索：Reason: image not found，但我不确定这是什么意思。

我在/usr/local/Cellar/mysql-connector-c中查看了一下我安装的连接器是否有什么可能丢失的东西，果然，libmysqlclient.21.dylib文件丢失了。取而代之的是我认为是旧版本的文件，因为它被命名为libmysqlclient.18.dylib。出于好奇，我复制了MySQL安装所带的.dylib并将该副本移动到相同名称的连接器文件夹和/usr/local/lib，在那里我还找到了另一个libmysqlclient.18.dylib文件。然而，我的迁移仍然失败了，但我确实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?

这次我遇到了以下错误:

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MySQL连接器安装的.dylib版本有关，但我不确定如何确切地解决这个问题。我发现仅仅复制一个文件就能微调我的堆栈跟踪，所以我想我应该更深入地研究一下这个问题。你有什么想法吗？

- Xoadra

Answer 1

只需在 /usr/local/lib 中创建一个符号链接。

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

- David Beckwith

---

完美运行，只需确保MySQL文件夹名称与您所拥有的相同。在我的情况下，它是 sudo ln -s /usr/local/mysql-8.0.19-macos10.15-x86_64/lib/libmysqlclient.21.dylib /usr/local/lib/libmysqlclient.21.dylib。 - Ziyad Sfaxi

非常感谢，这节省了我很多时间。 - Daniel Charles Mwangila

Answer 2

我最近在尝试在我的MacBook Pro（macOS Catallina）上安装Django和mod_wsgi时遇到了问题。设置LD_LIBRARY_PATH、DYLD_LIBRARY_PATH、添加符号链接以及将libmysqlclient.21.dylib文件移动到/usr/lib目录下都没有解决问题。我挣扎了几天，但最终找到了解决方案。关键是我需要修改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。看起来@rpath无法正常工作。

好的，您可以使用Xcode自带的otool检查.so文件中引用的路径。当您在mysql .so文件上运行它时，您会得到以下结果（应该在site-packages下的MySQLdb目录中）。

$ 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，我们在 _mysql.cpython-38-darwin.so 中修改了文件路径。有一个工具可以实现这一点，它就是 install_name_tool。我运行了以下命令：基本上我将 @rpath 更改为绝对路径，还将 libssl 和 licrypto 的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

在这些更改后，我的Django运行得非常好。

- yoshi

---

谢谢！这是在 Mac 上唯一有效的解决方案。 - Chris H

谢谢！对我也起作用了（MacOS Big Sur，MySQL 8，Python 3.8，Django 3.2.2）。虽然我只运行了你解决方案的第一行。看起来已经足够了。 - sipi09

老兄，你真是救星啊。我之前卡在这个问题上整整一天了。 - Pratik Saxena

这最好使用现有的通用软链接完成。类似于install_name_tool -change @rpath/libmysqlclient.21.dylib /usr/local/mysql/lib/libmysqlclient.dylib /Library/Frameworks/Python.framework/Versions/3.9/lib/python3.9/site-packages/MySQLdb/_mysql.cpython-39-darwin.so。 - Konchog

对于任何MacOS 14 - Sonoma的情况，答案是使用第一个命令将/opt/homebrew/opt/mysql/lib/libmysqlclient.21.dylib文件更改为/opt/homebrew/opt/mysql/lib/libmysqlclient.22.dylib，并将其应用于_mysql.cpython-310-darwin.so文件。 - Nicholas Gooding Rios

Answer 3

对我来说，在升级MySQL版本后，我遇到了一个问题。解决方法是重新安装mysqlclient Python依赖项，但只有在禁用缓存的情况下才有效，例如使用命令pip install --no-cache-dir mysqlclient。因为libmysqlclient.21.dylib已经被移除并替换为libmysqlclient.22.dylib，所以符号链接在这里无法起作用。

- Montaro

Answer 4

符号链接的解决方案对我有用，但在链接第一个文件后，我对于另一个文件名得到了相同的错误消息。总共，我需要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

- M3RS

---

感谢您提供的解决方案！我用它来安装DBD::mysql Perl模块，在MySQL 8.0.22，macOS Catalina和Perl 5.32中也遇到了这个问题。 - RickJansen

Answer 5

所以事实证明，我设法解决了我的问题，尽管方法有点不正规。如果其他人正在使用Python 3和MySQL 8的mysqlclient，请尝试一下，看看是否有帮助！：）

我只是在我的MySQL 8.0.13安装中复制了位于/usr/local/mysql/lib中的libmysqlclient.21.dylib文件，并将该副本移动到同名的/usr/lib目录下。

但是，您需要暂时禁用Mac上的安全完整性保护才能执行此操作，因为您无法在不禁用它的情况下拥有或更改/usr/lib中的任何权限。您可以通过启动恢复系统，在菜单上单击“实用工具”，然后打开终端并在终端中输入csrutil disable来执行此操作。完成此操作后，请记得重新启用安全完整性保护！与上述过程唯一的区别将是您运行csrutil enable而不是csrutil disable。

我完成了这个步骤后，在新数据库上像以前一样运行了我的迁移，它奏效了！老实说，我不知道这到底是一个多好的解决方案，但自从我更改了连接器使用的 .dylib 副本以来，一切都一直完美运行。如果你也遇到了这个问题，希望这可以帮到你！

你可以在这里阅读更多关于如何禁用和启用 macOS 安全完整性保护的信息。

- Xoadra

---

此外，您可以按照本文所述创建符号链接，我认为这比复制是一个稍微更好的解决方案： https://afshinm.name/2016/02/05/how-to-fix-library-not-loaded-libmysqlclient-18-dylib-in-mac-os-x/ - hellter

Answer 6

MacOS 14 - Sonoma的修复方法

经过大量搜索和艰难的时间，我终于找到了一个可能适用于任何MacOS用户的解决方案。如果您正在使用Sonoma MacOS 14，请按照以下步骤进行操作。

1. 检查出现的具体错误，并寻找以...开头的部分

ImportError: dlopen(.../_mysql.cpython-310-darwin.so) Library not loaded: /opt/homebrew/opt/mysql/lib/libmysqlclient.21.dylib

这两个部分非常重要，一个是尝试加载库的.so文件，另一个是被加载的.dylib库。

2. 在终端中进入包含so文件的文件夹

3. 在该文件夹中运行以下命令

otool -L _mysql.cpython-310-darwin.so

并搜索当前dylib版本它正在尝试查找

4. 转到/opt/homebrew/opt/mysql/lib/文件夹，并查找您的实际文件。在我的情况下，是一个名为libmysqlclient.22.dylib的符号链接文件，其实际文件名为libmysqlclient.dylib

5. 使用以下命令切换到正确的文件：

install_name_tool -change /opt/homebrew/opt/mysql/lib/{previous}.dylib /opt/homebrew/opt/mysql/lib/libmysqlclient.dylib _mysql.cpython-310-darwin.so

再次运行otool命令以查看更改。

otool -L _mysql.cpython-310-darwin.so

输出应为：

_mysql.cpython-310-darwin.so:
        /opt/homebrew/opt/mysql/lib/libmysqlclient.dylib (compatibility version 21.0.0, current version 21.0.0)
        /usr/lib/libresolv.9.dylib (compatibility version 1.0.0, current version 1.0.0)
        /usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1292.60.1)

这样做将解决错误，并让您继续进行DJango的迁移过程，或者让服务器再次正常运行，避免出现500错误。

- Nicholas Gooding Rios

---

成功了！在我的情况下，文件路径是/gems/mysql2-0.5.3/lib/mysql2/mysql2.bundle，错误信息为/gems/mysql2-0.5.3/lib/mysql2/mysql2.bundle，0x0009）：无法加载库：/opt/homebrew/opt/mysql/lib/libmysqlclient.21.dylib（LoadError） - undefined

Answer 7

我的Python 3.6项目需要使用libmysqlclient.21.dylib库。我使用brew install mysql-client进行安装，它安装了mysql-client 8.0版本，并且其中包含了libmysqlclient.21.dylib库。但是我想要使用mysql@5.6。因此，我将/usr/local/Cellar/mysql-client/8.0.19/lib中的libmysqlclient.21.dylib复制到了/usr/local/lib/目录下。

然后我使用以下命令：sudo ln -s /usr/local/Cellar/mysql-client/8.0.19/lib/libmysqlclient.21.dylib /usr/local/lib/libmysqlclient.21.dylib

- Mushtaque Ahmed

Answer 8

我尝试了很多方法，但最终发现只需要将文件夹mysql-8.0.26-macos11-x86_64重命名为“mysql”，放在usr/local/mysql-8.0.26-macos11-x86_64/lib/libmysqlclient.21.dylib中即可。一旦我这样做了，一切都正常了。

- lemma5678

Answer 9

在我的情况下，我发现问题的根本原因是相对路径。所以将其更改为绝对路径解决了这个问题。

进入包含 `_mysql.cpython-310-darwin.so` 文件的目录。

使用以下命令检查路径：

otool -L _mysql.cpython-310-darwin.so

在我的情况下，这就是返回的内容。

@rpath/libmysqlclient.21.dylib (compatibility version 21.0.0, current version 21.0.0)

将此更改为绝对路径解决了问题。

install_name_tool -change @rpath/libmysqlclient.21.dylib /usr/local/mysql/lib/libmysqlclient.21.dylib _mysql.cpython-310-darwin.so

现在当你再次使用上述相同的命令检查路径时

otool -L _mysql.cpython-310-darwin.so

绝对路径应该像这样返回

/usr/local/mysql/lib/libmysqlclient.21.dylib (compatibility version 21.0.0, current version 21.0.0)

- Dennis