Github Actions拉取请求报错：Git版本参数歧义问题求助

本人仅会基础的git push和git pull操作，在GitHub Actions的拉取请求（pull request）触发流程中遇到错误，报错提示git diff的版本参数存在歧义，未知该版本或路径不在工作树中。已尝试孤立分支、重建仓库等方法，仍未解决，且另一同配置的API仓库无此问题。

报错信息 #

Run FORBIDDEN_FILES=("appsettings.json" "program.cs")
  FORBIDDEN_FILES=("appsettings.json" "program.cs")
  for FILE in "${FORBIDDEN_FILES[@]}"; do
    echo "Checking $FILE"
    if git diff --name-only origin/dev_branch..0a7488a784a893ab515dbd8853a32009d3f0d83d | grep -q "^$FILE$"; then
      echo "Error: You are trying to merge changes to a forbidden file: $FILE"
      exit 1
    fi
  done
  shell: /usr/bin/bash -e {0}
Checking appsettings.json
fatal: ambiguous argument 'origin/dev_branch..0a7488a784a893ab515dbd8853a32009d3f0d83d': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'
Checking program.cs
fatal: ambiguous argument 'origin/dev_branch..0a7488a784a893ab515dbd8853a32009d3f0d83d': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'

对应的GitHub Actions代码 #

name: Check Forbidden Files

on: pull_request

jobs:
  check:
    runs-on: ubuntu-latest
    steps:
    - name: Checkout code
      uses: actions/checkout@v3

    - name: Check for forbidden file changes
      run: |
        FORBIDDEN_FILES=("appsettings.json" "program.cs")
        for FILE in "${FORBIDDEN_FILES[@]}"; do
          echo "Checking $FILE"
          if git diff --name-only origin/${{ github.base_ref }}..${{ github.sha }} | grep -q "^$FILE$";     then
            echo "Error: You are trying to merge changes to a forbidden file: $FILE"
            exit 1
          fi
        done

• 拉取完整仓库历史与远程分支：默认的actions/checkout@v3只会拉取当前提交的代码，不会获取远程分支的完整信息。修改checkout步骤，添加fetch-depth: 0参数拉取所有历史，同时显式拉取目标分支：

  - name: Checkout code
    uses: actions/checkout@v3
    with:
      fetch-depth: 0 # 拉取完整仓库历史
  - name: Fetch target branch
    run: git fetch origin ${{ github.base_ref }}
  

• 修正git diff的参数格式：报错提示参数歧义，可在git diff末尾添加--明确分隔版本和路径（即使这里没有路径参数，也能避免歧义），同时确保引用的分支或提交存在：

  git diff --name-only origin/${{ github.base_ref }}..${{ github.sha }} --
  

• 改用GitHub提供的PR对比变量：在PR触发的Actions中，GitHub提供了github.event.pull_request.base.sha和github.event.pull_request.head.sha，直接用这两个变量对比更可靠，避免分支名引用的问题：

  git diff --name-only ${{ github.event.pull_request.base.sha }}..${{ github.event.pull_request.head.sha }} --
  

• 验证提交存在性：在执行git diff前先检查提交是否存在，避免无效引用：

  if ! git rev-parse --verify origin/${{ github.base_ref }} > /dev/null 2>&1; then
    echo "Error: Base branch origin/${{ github.base_ref }} not found"
    exit 1
  fi
  if ! git rev-parse --verify ${{ github.sha }} > /dev/null 2>&1; then
    echo "Error: Head commit ${{ github.sha }} not found"
    exit 1
  fi
  

内容的提问来源于stack exchange，提问作者Alexander Fields