[nickcw]

> 1. Environment variables can only be defined on steps, they can't be defined at a job level

Actually you can define global environment variables with an extra step... here is how I do it. I was quite frustrated until I worked this out!

      - name: Set environment variables
        shell: bash
        run: |
          echo '::set-env name=GOPATH::${{ runner.workspace }}'
          echo '::add-path::${{ runner.workspace }}/bin'
          echo '::set-env name=GO111MODULE::${{ matrix.modules }}'
          echo '::set-env name=GOTAGS::${{ matrix.gotags }}'
          echo '::set-env name=BUILD_FLAGS::${{ matrix.build_flags }}'

[satyadeepk]

That actually works! Thank you.