name: better-setup-go
description: Install a pinned Go toolchain from the official static tarball — musl-safe, no manifest fetches, Forgejo/act runner safe.
inputs:
  go-version:
    description: Exact Go version to install (e.g. 1.27.0).
    required: true
runs:
  using: composite
  steps:
    - shell: bash
      run: |
        set -euo pipefail
        v="${{ inputs.go-version }}"
        case "$(uname -m)" in
          x86_64|amd64) arch=amd64 ;;
          aarch64|arm64) arch=arm64 ;;
          *) echo "better-setup-go: unsupported arch $(uname -m)" >&2; exit 1 ;;
        esac
        rm -rf /usr/local/go   # a base-image GOROOT under the same path corrupts on overlay
        # download-to-file with retries: a piped stream that truncates mid-archive leaves a
        # half-extracted GOROOT that fails far away from its cause
        curl --retry 3 --retry-delay 2 -fsSL -o /tmp/go.tgz "https://go.dev/dl/go${v}.linux-${arch}.tar.gz"
        tar -xzf /tmp/go.tgz -C /usr/local
        rm -f /tmp/go.tgz
        ln -sf /usr/local/go/bin/go /usr/local/bin/go
        ln -sf /usr/local/go/bin/gofmt /usr/local/bin/gofmt
        go version