Support for Outputting or Exporting Go Environment Variables

Version

actions/setup-go@v2

Description

In some of our GitHub Actions workflows, we opt to cache the GOCACHE between jobs to save compilation time. It seems like we currently need to run go env GOCACHE to fetch the correct GOCACHE path after this action is run, e.g.

jobs:
  example:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v2
    - uses: actions/setup-go@v2
      with:
        go-version: "1.14"
    - name: go env
      run: |
        echo "::set-env name=GOCACHE::$(go env GOCACHE)"
    - uses: actions/cache@v2
      with:
        path: ${{ env.GOCACHE }}
        key: ${{ runner.os }}-GOCACHE-${{ hashFiles('go.sum') }}-${{ hashFiles('src/**') }}

Since this action already runs go env, it would be great if those values were either available as outputs, e.g.

jobs:
  example:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v2
    - uses: actions/setup-go@v2
      id: setup_go
      with:
        go-version: "1.14"
    - uses: actions/cache@v2
      with:
        path: ${{ steps.setup_go.outputs.GOCACHE }}
        key: ${{ runner.os }}-GOCACHE-${{ hashFiles('go.sum') }}-${{ hashFiles('src/**') }}

Or if we could configure environment variables to automatically be exported:

jobs:
  example:
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v2
    - uses: actions/setup-go@v2
      with:
        go-version: "1.14"
        export-environment-variables: [GOCACHE]
    - uses: actions/cache@v2
      with:
        path: ${{ env.GOCACHE }}
        key: ${{ runner.os }}-GOCACHE-${{ hashFiles('go.sum') }}-${{ hashFiles('src/**') }}

Thank you for the consideration! Please reach out if I'm missing something and this is already possible or if this would be acceptable as an enhancement.