rfl：从 lean 开始的异世界生活（2）——安装 lean copilot

按照 github repo 的安装方法：

先在 lakefile.lean 中加入 Lean Copilot 作为 dependency，对于 lakefile.toml，可自行查阅 github 上的 readme．

package «my-package» {
  moreLinkArgs := #[
    "-L./.lake/packages/LeanCopilot/.lake/build/lib",
    "-lctranslate2"
  ]
}

require LeanCopilot from git "https://github.com/lean-dojo/LeanCopilot.git" @ "v4.21.0"

注意这里 Lean Copilot 的版本和 mathlib 版本最好一样，不然会有一堆莫名报错．

If you are using native Windows, add <path_to_your_project>/.lake/packages/LeanCopilot/.lake/build/lib to your Path variable in Advanced System Settings > Environment Variables... > System variables.

然后 lake update LeanCopilot．如果正好需要更新 lean 工具链，可以使用 SJTU 提供的 glean．

到这里应该一切正常了．但是接下来按官方说明，

lake exe LeanCopilot/download

就会喜提报错：

✖ [3473/3580] Building LeanCopilot/libctranslate2
info: Cloning CTranslate2 from https://github.com/OpenNMT/CTranslate2
info: Configuring CTranslate2 with `cmake -DOPENMP_RUNTIME=NONE -DWITH_MKL=OFF -DWITH_ACCELERATE=OFF -DWITH_OPENBLAS=ON -DOPENBLAS_INCLUDE_DIR=../../OpenBLAS -DOPENBLAS_LIBRARY=../../OpenBLAS/libopenblas.so ..`
error: Failed to run cmake

看了一眼我 cmake 版本也不低啊？那怎么回事呢？

尝试切进目录手动执行 cmake 命令：

cd .lake/packages/LeanCopilot/.lake/build/CTranslate2/build
cmake -DOPENMP_RUNTIME=NONE -DWITH_MKL=OFF -DWITH_ACCELERATE=OFF -DWITH_OPENBLAS=ON -DOPENBLAS_INCLUDE_DIR=../../OpenBLAS -DOPENBLAS_LIBRARY=../../OpenBLAS/libopenblas.so ..

CMake Deprecation Warning at CMakeLists.txt:1 (cmake_minimum_required):
  Compatibility with CMake < 3.10 will be removed from a future version of CMake.

  Update the VERSION argument <min> value.  Or, use the <min>...<max> syntax          
  to tell CMake that the project requires at least <min> but has been updated
  to work with policies introduced by <max> or earlier.


-- Build spdlog: 1.10.0
-- Build type: Release
CMake Error at third_party/cpu_features/CMakeLists.txt:1 (cmake_minimum_required):
  Compatibility with CMake < 3.5 has been removed from CMake.

  Update the VERSION argument <min> value.  Or, use the <min>...<max> syntax
  to tell CMake that the project requires at least <min> but has been updated
  to work with policies introduced by <max> or earlier.

  Or, add -DCMAKE_POLICY_VERSION_MINIMUM=3.5 to try configuring anyway.


-- Configuring incomplete, errors occurred! 

原来是 cmake 版本太高了．在 .lake/packages/LeanCopilot/.lake/build/CTranslate2/ 目录里，手动修改一下 ../third_party/cpu_features/CMakeLists.txt，把 cmake_minimum_required 调高就行了．

然后重新跑，报了一屏幕的 c++ 编译错误．修改 ../third_party/cxxopts/include/cxxopts.hpp，加入 #include <cstdint>．

跑起来了，但是 huggingface 访问缓慢，于是在 hf-mirror.com 镜像站上把 github readme 里提到的四个 repo clone 进 ~/.cache/lean_copilot/models/huggingface.co/kaiyuy/ct2-byt5-small 里．

试一下 lake build，没有问题．在代码里 import LeanCopilot 即可使用．

使用体验

由于一些神秘原因，只能用 CPU 跑．

烟瘾丁真，鉴定为：纯纯的肺雾．