问题描述

Ubuntu 20.04 使用 pip 安装 transformers 库遇到报错：error: can't find Rust compiler. 下面是报错信息的后半部分。 

running build_ext
      running build_rust
      error: can't find Rust compiler

      If you are using an outdated pip version, it is possible a prebuilt wheel is available for this package but pip is not able to install from it. Installing from the wheel would avoid the need for a Rust compiler.

      To update pip, run:

          pip install --upgrade pip

      and then retry package installation.

      If you did intend to build this package from source, try installing a Rust compiler from your system package manager and ensure it is on the PATH during installation. Alternatively, rustup (available at https://rustup.rs) is the recommended way to download and update the Rust compiler toolchain.
      [end of output]

  note: This error originates from a subprocess, and is likely not a problem with pip.
  ERROR: Failed building wheel for tokenizers
Failed to build tokenizers
ERROR: Could not build wheels for tokenizers, which is required to install pyproject.toml-based projects

解决方案

sudo apt install rustc
sudo apt install cargo

完成上面两个库的安装重新执行 transformers 的安装即可，库较大可能需要 build 一段时间。（我这边用时2分钟左右）

pip install transformers

详细流程

按照提示更新了 pip:

pip install --upgrade pip

但是没有任何作用。报错信息不变。那只能考虑安装 Rust。

参考资料：How to Install Rust on Ubuntu {apt and rustup}

这个用 apt 安装的看上去是最简单的：

sudo apt install rustc

安装完毕后依旧报错：

      error: [Errno 2] No such file or directory: 'cargo'
      [end of output]

  note: This error originates from a subprocess, and is likely not a problem with pip.
  ERROR: Failed building wheel for tokenizers
Failed to build tokenizers
ERROR: Could not build wheels for tokenizers, which is required to install pyproject.toml-based projects

然后测试 apt 安装。

sudo apt install cargo

然后重新 pip 安装，问题解决。

相关工作

Windows 下同样问题的解决可参考：安装transformers报错error can‘t find rust compiler_can't find rust compiler-CSDN博客