name: Setup Rust toolchain (with retry)
description: >
  Install a Rust toolchain via dtolnay/rust-toolchain, retrying once after a
  short pause on the transient rustup CDN failure (a corrupt channel manifest /
  checksum mismatch on `channel-rust-<channel>.toml`) that rustup itself does
  not retry — the same hardening already applied to setup-node / setup-go.

inputs:
  toolchain:
    description: Rust toolchain (channel or version) to install.
    required: false
    default: stable
  components:
    description: Comma-separated list of rustup components (e.g. "rustfmt, clippy").
    required: false
    default: ""
  targets:
    description: Comma-separated list of rustup targets (e.g. "wasm32-unknown-unknown").
    required: false
    default: ""

runs:
  using: composite
  steps:
    - id: first
      uses: dtolnay/rust-toolchain@29eef336d9b2848a0b548edc03f92a220660cdb8 # zizmor: ignore[impostor-commit] pinned to the stable-tag SHA (2026-03-27); tag-pinned, not a branch commit
      continue-on-error: true
      with:
        toolchain: ${{ inputs.toolchain }}
        components: ${{ inputs.components }}
        targets: ${{ inputs.targets }}

    - name: Wait before retrying the toolchain install
      if: steps.first.outcome == 'failure'
      shell: bash
      run: |
        echo "::warning::rustup toolchain install failed (likely a CDN flake / corrupt channel manifest); retrying in 30s"
        sleep 30

    - name: Retry the Rust toolchain install
      if: steps.first.outcome == 'failure'
      uses: dtolnay/rust-toolchain@29eef336d9b2848a0b548edc03f92a220660cdb8 # zizmor: ignore[impostor-commit] pinned to the stable-tag SHA (2026-03-27); tag-pinned, not a branch commit
      with:
        toolchain: ${{ inputs.toolchain }}
        components: ${{ inputs.components }}
        targets: ${{ inputs.targets }}