How to setup default rust compilation target on CI using rustup command on github actions?

Question

I need to compile my code for both 32 and 64 bit windows. As far as I understand, I basically need to configure my CI so that this command:

rustup default

prints

stable-i686-pc-windows-msvc (default)

(i build a lot of stuff in one run, including a tauri app, and they all need to detect that as the compilation target)

this didn't work (it still prints x86_64 on both runs)

jobs:
  publish-tauri:
    strategy:
      fail-fast: true
      matrix:
        settings:
          - host: windows-latest
            target: x86_64-pc-windows-msvc
          - host: windows-latest
            target: i686-pc-windows-msvc

    runs-on: ${{ matrix.settings.host }}
    steps:
      - name: Install rust toolchain
        uses: actions-rs/toolchain@v1
        with:
          profile: minimal
          override: true
          default: true
          toolchain: stable
          target: ${{ matrix.settings.target }}

      - name: REALLY set default target # based on https://rust-lang.github.io/rustup/installation/windows.html
        run: rustup set default-host ${{ matrix.settings.target }}

Answer 1

Would providing build matrix data as arrays work? Like:

jobs:
  publish-tauri:
    strategy:
      fail-fast: true
      matrix:
        toolchain: [stable]
        os: [windows-latest]
        target: [x86_64-pc-windows-msvc, i686-pc-windows-msvc]

    runs-on: ${{ matrix.os }}

    steps:
      - name: Install rust toolchain
        uses: actions-rs/toolchain@v1
        with:
          profile: minimal
          override: true
          default: true
          toolchain: ${{ matrix.toolchain }}
          target: ${{ matrix.target }}