github-actions - 如何在GitHub Actions表达式语法中引用上下文值？

Question

我想在GitHub Action的env:部分设置一个环境变量，并使用Contexts and expression syntax for GitHub Actions。我尝试了这个:

jobs:
  build:
    runs-on: ubuntu-latest

    env:
      MYVAR: ${{ format('{0}:{1}', ${{ env.PATH }}, ${{ env.HOME }} ) }}

    steps:
    - name: Check environment
      run: echo $MYVAR

这将导致错误消息:

### ERRORED 10:45:52Z

- Your workflow file was invalid: The pipeline is not valid. .github/workflows/main.yml (Line: 10, Col: 14): Unexpected symbol: '${{'. Located at position 19 within expression: format('{0}:{1}', ${{ env.PATH

这个语法:

    env:
      MYVAR: ${{ format('{0}:{1}', {{ env.PATH }}, {{ env.HOME }} ) }}

导致错误:

### ERRORED 13:14:18Z

- Your workflow file was invalid: The pipeline is not valid. .github/workflows/main.yml (Line: 10, Col: 14): Unexpected symbol: '{{'. Located at position 19 within expression: format('{0}:{1}', {{ env.PATH

和:

    env:
      MYVAR: ${{ format('{0}:{1}', env.PATH, env.HOME ) }}

导致错误:

### ERRORED 13:16:12Z

- Your workflow file was invalid: The pipeline is not valid. .github/workflows/main.yml (Line: 10, Col: 14): Unrecognized named-value: 'env'. Located at position 19 within expression: format('{0}:{1}', env.PATH, env.HOME )

我知道How do i set an env var with a bash expression in GitHub Actions?和Github Actions, how to share a calculated value between job steps?中用于设置环境变量的解决方案，但是我想了解表达式语法。

Answer 1

正如@jonrsharpe所指出的，不可能在工作流环境变量的值中使用env上下文。这里讨论了这一点:

https://github.community/t5/GitHub-Actions/How-to-use-env-context/td-p/38951