unstructured 包安装报错 Building wheel for lxml (pyproject.toml) did not run successfully.

现象：

在2025-06-27 安装 unstructured 包时，报错Building wheel for lxml (pyproject.toml) did not run successfully.

报错信息

Building wheel for lxml (pyproject.toml) did not run successfully.
  │ exit code: 1
  ╰─> [4856 lines of output]
      Building lxml version 6.0.0.
      Building without Cython.
      Building against libxml2 2.9.1 and libxslt 1.1.28
      running bdist_wheel
      running build
      running build_py
      
      …………
 note: This error originates from a subprocess, and is likely not a problem with pip.
  ERROR: Failed building wheel for lxml
Failed to build lxml
ERROR: Could not build wheels for lxml, which is required to install pyproject.toml-based projects

Python版本

python 3.8

unstructured版本

unstructured==0.11.8

原因

在2025-06-27 lxml更新了6.0 版本，unstructured安装lxml依赖时没指定包版本，安装了lxml的6.0版本，但是lxml构建失败导致安装unstructured报错

解决方法

在unstructured安装前指定lxml版本（上一个版本为lxml == 5.4.0
），如：

lxml==5.4.0
unstructured==0.11.8