ci: publish furrow binaries for linux and macOS

.github/workflows/release.yml

@@ -0,0 +1,102 @@
+name: release
+
+# Publishes per-platform `furrow` binaries so callers can install it without a
+# Rust toolchain. Windows is absent on purpose: 13 source files use
+# `std::os::unix` with no `cfg(windows)` guards, so a native Windows build needs
+# a source port, not a build target. Windows users reach furrow through WSL,
+# which uses the linux asset.
+
+on:
+  push:
+    tags:
+      - "v*"
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: "Existing tag to build and publish (e.g. v0.1.0)"
+        required: true
+        type: string
+
+permissions:
+  contents: write
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  build:
+    name: ${{ matrix.asset }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - asset: furrow-linux-amd64
+            target: x86_64-unknown-linux-gnu
+            os: ubuntu-latest
+            native: true
+          - asset: furrow-darwin-arm64
+            target: aarch64-apple-darwin
+            os: macos-14
+            native: true
+          # Cross-compiled on the arm64 runner; Apple's toolchain ships both
+          # slices, so this needs no extra SDK. It cannot be smoke-tested here.
+          - asset: furrow-darwin-amd64
+            target: x86_64-apple-darwin
+            os: macos-14
+            native: false
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ inputs.tag || github.ref }}
+
+      - name: Install toolchain
+        run: |
+          rustup toolchain install stable --profile minimal --no-self-update
+          rustup target add ${{ matrix.target }}
+
+      - name: Build
+        run: cargo +stable build --release --locked --target ${{ matrix.target }}
+
+      - name: Smoke test
+        if: matrix.native
+        run: ./target/${{ matrix.target }}/release/furrow --version
+
+      - name: Stage asset
+        run: |
+          mkdir -p dist
+          install -m 755 "target/${{ matrix.target }}/release/furrow" "dist/${{ matrix.asset }}"
+
+      - uses: actions/upload-artifact@v4
+        with:
+          name: ${{ matrix.asset }}
+          path: dist/${{ matrix.asset }}
+          if-no-files-found: error
+
+  publish:
+    needs: build
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/download-artifact@v4
+        with:
+          path: dist
+          merge-multiple: true
+
+      - name: Checksums
+        working-directory: dist
+        run: sha256sum furrow-* > SHA256SUMS
+
+      - name: Publish release
+        env:
+          GH_TOKEN: ${{ github.token }}
+          TAG: ${{ inputs.tag || github.ref_name }}
+        run: |
+          if gh release view "$TAG" --repo "$GITHUB_REPOSITORY" >/dev/null 2>&1; then
+            gh release upload "$TAG" dist/* --repo "$GITHUB_REPOSITORY" --clobber
+          else
+            gh release create "$TAG" dist/* \
+              --repo "$GITHUB_REPOSITORY" \
+              --title "furrow $TAG" \
+              --generate-notes \
+              --verify-tag
+          fi