chore(ci): update tarball workflow in GitHub Actions

.github/workflows/tarball.yml

@@ -4,42 +4,47 @@ on:
     branches: [ master ]
   workflow_dispatch:
 
+jobs:
+  dist:
+    runs-on: ubuntu-latest
+    steps:
+name: snapshot-dist-tarball
+on:
+  push:
+    branches: [ master ]
+  workflow_dispatch:
+
 jobs:
   dist:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-        with:
-          fetch-depth: 0        # git describe needs full history
+        with: {fetch-depth: 0}
 
-      - name: Install autotools
-        run: sudo apt-get update && sudo apt-get -y install autoconf automake libtool texinfo libltdl-dev texlive
-
-      - name: Stamp snapshot version into configure.ac
+      - name: Compute snapshot VERSION
+        id: ver
         run: |
-          VERSION="$(git describe --tags --long --match 'v[0-9]*' | sed -e 's/^v//' -e 's/-/.dev./' -e 's/-/+g/')"
-          echo "VERSION=$VERSION" >> "$GITHUB_ENV"
+          DESC=$(git describe --long --tags --match 'v[0-9]*' 2>/dev/null || echo "")
+          VERSION=$(echo "$DESC" | sed -E 's/^v//; s/-([0-9]+)-g/\.dev.\1+g/')
+          if [[ -z "$VERSION" || "$VERSION" == "$DESC" ]]; then
+            VERSION="3.5.1-dev.0+g$(git rev-parse --short HEAD)"
+          fi
+          echo "VERSION=$VERSION"           >> "$GITHUB_ENV"
+          echo "version=$VERSION"           >> "$GITHUB_OUTPUT"
 
-          # 1) AC_INIT second argument
-          # AC_INIT([libffi],[<old>],[bug-address])
-          sed -E -i "s/^(AC_INIT\(\[libffi\],\s*\[)[^]]+/\1$VERSION/" configure.ac
+      - name: Patch configure.ac
+        run: |
+          sed -Ei "s/^(AC_INIT\(\[libffi\],\s*\[)[^]]+/\1${VERSION}/" configure.ac
+          sed -Ei "s/^(FFI_VERSION_STRING=\")[^\"]+/\1${VERSION}/"    configure.ac
 
-          # 2) FFI_VERSION_STRING="..."
-          sed -E -i "s/^(FFI_VERSION_STRING=\")[^\"]+/\1$VERSION/" configure.ac
-
-      - name: autogen
-        run: ./autogen.sh
-
-      - name: Configure
-        run: ./configure
-
-      - name: Build dist tarball
-        run: make dist
+      - run: autoreconf -fi
+      - run: ./configure
+      - run: make dist     # produces libffi-${VERSION}.tar.gz
 
       - name: Create (or update) “snapshots” release
         uses: softprops/action-gh-release@v2
-        with:
-          tag_name: snapshots
-          prerelease: true
-          body: "Snapshot built from ${{ github.sha }}"
-          files: libffi-${{ env.VERSION }}.tar.*
+          with:
+            tag_name: snapshots
+            prerelease: true
+            body: "Nightly snapshot built from ${{ github.sha }}"
+            files: libffi-${{ env.VERSION }}.tar.*