Question: I'm using python:3-slim Docker image and want to use the mysqlclient package from Pypi but getting the following error from RUN pip install mysqlclient command: ... Collecting mysqlclient Downloading mysqlclient-2.2.0.tar.gz (89 kB) ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 89.5/89.5 kB 2.5 MB/s eta 0:00:00 Installing build dependencies: started Installing build dependencies: finished with status 'done' Getting requirements to build wheel: started Getting requirements to build wheel: finished with status 'error' error: subprocess-exited-with-error × Getting requirements to build wheel did not run successfully. │ exit code: 1 ╰─> [27 lines of output] /bin/sh: 1: pkg-config: not found /bin/sh: 1: pkg-config: not found Trying pkg-config --exists mysqlclient Command 'pkg-config --exists mysqlclient' returned non-zero exit status 127. Trying pkg-config --exists mariadb Command 'pkg-config --exists mariadb' returned non-zero exit status 127. Traceback (most recent call last): File "/usr/local/lib/python3.12/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 353, in <module> main() File "/usr/local/lib/python3.12/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 335, in main json_out['return_val'] = hook(**hook_input['kwargs']) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/usr/local/lib/python3.12/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 118, in get_requires_for_build_wheel return hook(config_settings) ^^^^^^^^^^^^^^^^^^^^^ File "/tmp/pip-build-env-f_fea8lo/overlay/lib/python3.12/site-packages/setuptools/build_meta.py", line 355, in get_requires_for_build_wheel return self._get_build_requires(config_settings, requirements=['wheel']) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ File "/tmp/pip-build-env-f_fea8lo/overlay/lib/python3.12/site-packages/setuptools/build_meta.py", line 325, in _get_build_requires self.run_setup() File "/tmp/pip-build-env-f_fea8lo/overlay/lib/python3.12/site-packages/setuptools/build_meta.py", line 341, in run_setup exec(code, locals()) File "<string>", line 154, in <module> File "<string>", line 48, in get_config_posix File "<string>", line 27, in find_package_name Exception: Can not find valid pkg-config name. Specify MYSQLCLIENT_CFLAGS and MYSQLCLIENT_LDFLAGS env vars manually [end of output] note: This error originates from a subprocess, and is likely not a problem with pip. error: subprocess-exited-with-error × Getting requirements to build wheel did not run successfully. │ exit code: 1 ╰─> See above for output.  My Dockerfile looks like: FROM python:3.12-slim RUN pip install mysqlclient  I tried installing the build dependencies by adding the following to the Dockerfile above RUN pip install mysqlclient: RUN apt-get install python3-dev default-libmysqlclient-dev build-essential  but this took the Docker image to over 700MB. I also tried replacing the line above with the following to remove the build dependencies after install mysqlclient: RUN apt-get update && \ apt-get dist-upgrade && \ apt-get install -y pkg-config default-libmysqlclient-dev \ build-essential libmariadb-dev && \ pip install mysqlclient && \ apt-get purge -y pkg-config default-libmysqlclient-dev build-essential  but the resulting image was still over 500MB in size and took a lot of precious CI/CD build time as it installs and then uninstalls the build tools. How do I install mysqlclient without bloating my docker image with build dependencies?

Answer: Use a Multi-Stage build Dockerfile: FROM python:3.12 AS python-build RUN pip install mysqlclient FROM python:3.12-slim COPY --from=python-build /usr/local/lib/python3.12/site-packages /usr/local/lib/python3.12/site-packages RUN apt-get update && apt-get install -y libmariadb3  This first 'stage' uses a full-fat python:3.12 image, which has the necessary build tools to install and compile mysqlclient. As is typical with Python, the mysqlclient package along with its dependencies are installed in /usr/local/lib/python*/site-packages. Then the build starts again, this time using python:3.12-slim image. The COPY references the first image and copies just the installed Python packages including mysqlclient. The final line installs libmariadb3, which is required by mysqlclient, otherwise you'll receive the following error: ImportError: libmariadb.so.3: cannot open shared object file: No such file or directory  Your image size should now be a little over 190MB. You'll find it'll build much quicker too.