GHA可重用工作流：workflow_dispatch成功但push触发失败

问题背景 #

我有3个GitHub Actions工作流，其中reusable.yml位于独立仓库：

push-client.yml（推送触发） #

name: Execute on push

on:
  push: 

jobs:
  deploy: 
    uses: <my-org>/<reusable-workflow-repo>/.github/workflows/reusable.yml@main
    with:
      runner: 'WinRunner1'
      import-submodules: 'recursive'
    secrets:
      repo_token: ${{ secrets.REPO_READ_PAT }}

workflow-dispatch.yml（手动触发） #

name: Execute on manual click

on:
  workflow_dispatch:
    inputs:
      runner:
        required: true
        type: choice
        options:
          - 'WinRunner1'
          - 'WinRunner2'
      import-submodules:
        type: choice
        required: true
        options:
          - 'recursive' #All submodule levels
          - 'true' #Only first submodule level
          - 'false'

jobs:
  deploy: 
    #name: Call Reusable Workflow
    uses: <my-org>/<my-reusable-repo>/.github/workflows/reusable.yml@main
    with:
      runner: ${{ github.event.inputs.runner }}
      import-submodules: ${{ github.event.inputs.import-submodules }}
    secrets:
      repo_token: ${{ secrets.REPO_READ_PAT }}

reusable.yml（可复用工作流） #

name: Reusable 

on:
  workflow_call:
    inputs:
      runner:
        required: true
        type: string
      import-submodules:
        type: string
        required: true
    secrets:
      repo_token:
        description: 'PAT with access to caller repo + submodules. If no submodules, native GITHUB_TOKEN works.'
        required: true

jobs:
  checkout: 
    runs-on: ${{ github.event.inputs.runner }}
    steps:
      - name: Checkout Repository without Submodules
        uses: actions/checkout@v4
        if: ${{ github.event.inputs.import-submodules == 'false' }}
        with:
          token: ${{ secrets.REPO_TOKEN }}
      - name: Checkout Repository with Submodules
        uses: actions/checkout@v4
        if: ${{ github.event.inputs.import-submodules == 'true' }}
        with:
          submodules: true
          token: ${{ secrets.REPO_TOKEN }}
      - name: Checkout Repository with Recursive Submodules
        uses: actions/checkout@v4
        if: ${{ github.event.inputs.import-submodules == 'recursive' }}
        with:
          submodules: recursive
          token: ${{ secrets.REPO_TOKEN }}
      - name: Checkout reusable workflow's repo to access Python scripts hosted there
        uses: actions/checkout@v4
        with:
          repository: <my-org>/<reusable-workflow-repo>
          token: ${{ secrets.REPO_TOKEN }}
          path: reusable-workflow-repo

问题现象 #

workflow-dispatch.yml手动触发能正常执行，但push-client.yml在代码推送触发时执行失败，错误信息如下：

Error when evaluating 'runs-on' for job 'checkout'. <my-org>/<reusable-workflow-repo>/.github/workflows/reusable.yml@main (Line: 19, Col: 14): Unexpected value ''

问题原因 #

核心问题是可复用工作流的参数引用逻辑错误：

• 当工作流由workflow_dispatch手动触发时，github.event.inputs确实能获取到用户选择的参数，所以workflow-dispatch.yml能正常运行。
• 但当通过其他工作流（比如push-client.yml）调用可复用工作流时，传入的参数属于workflow_call定义的输入，此时应该用${{ inputs.xxx }}来引用，而非github.event.inputs。
• push-client.yml触发时，github.event是push事件，不存在inputs字段，所以${{ github.event.inputs.runner }}会返回空字符串，导致runs-on的值为空，直接触发错误。

修复方案 #

修改reusable.yml中的所有参数引用，把github.event.inputs替换为inputs，修改后的代码如下：

name: Reusable 

on:
  workflow_call:
    inputs:
      runner:
        required: true
        type: string
      import-submodules:
        type: string
        required: true
    secrets:
      repo_token:
        description: 'PAT with access to caller repo + submodules. If no submodules, native GITHUB_TOKEN works.'
        required: true

jobs:
  checkout: 
    runs-on: ${{ inputs.runner }}
    steps:
      - name: Checkout Repository without Submodules
        uses: actions/checkout@v4
        if: ${{ inputs.import-submodules == 'false' }}
        with:
          token: ${{ secrets.REPO_TOKEN }}
      - name: Checkout Repository with Submodules
        uses: actions/checkout@v4
        if: ${{ inputs.import-submodules == 'true' }}
        with:
          submodules: true
          token: ${{ secrets.REPO_TOKEN }}
      - name: Checkout Repository with Recursive Submodules
        uses: actions/checkout@v4
        if: ${{ inputs.import-submodules == 'recursive' }}
        with:
          submodules: recursive
          token: ${{ secrets.REPO_TOKEN }}
      - name: Checkout reusable workflow's repo to access Python scripts hosted there
        uses: actions/checkout@v4
        with:
          repository: <my-org>/<reusable-workflow-repo>
          token: ${{ secrets.REPO_TOKEN }}
          path: reusable-workflow-repo

修改完成后，无论是手动触发还是推送触发，可复用工作流都能正确获取传入的参数，push-client.yml即可正常执行。

内容的提问来源于stack exchange，提问作者jrbe228