feat: build gate + inert wiring for contrib Delta scans [Delta contrib split, part 2]

.github/workflows/delta_build_gate.yml

@@ -0,0 +1,92 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+
+# Build-gate verification for the optional contrib/delta integration.
+#
+# A single cheap job that runs dev/verify-contrib-delta-gate.sh, which proves:
+#   - the DEFAULT cargo / mvn / dylib build carries ZERO Delta surface
+#     (no comet-contrib-delta / delta_kernel in the cargo tree, no io.delta in
+#     the effective pom, no Delta symbols in libcomet); and
+#   - the gated build (`--features contrib-delta` / `-Pcontrib-delta`) compiles
+#     and pulls the right delta-spark per Spark profile.
+#
+# The full contrib Scala suite + regression workflows land later (A.6a/A.6b);
+# this minimal gate is all the build-gate + inert-wiring unit needs.
+
+name: Delta Contrib Build Gate
+
+concurrency:
+  group: ${{ github.repository }}-${{ github.head_ref || github.sha }}-${{ github.workflow }}
+  cancel-in-progress: true
+
+on:
+  push:
+    branches:
+      - main
+    paths-ignore:
+      - "benchmarks/**"
+      - "doc/**"
+      - "docs/**"
+      - "**.md"
+      - "dev/changelog/*.md"
+      - "native/core/benches/**"
+      - "native/spark-expr/benches/**"
+      - "spark/src/main/scala/org/apache/comet/GenerateDocs.scala"
+      - "spark-integration/**"
+  pull_request:
+    paths-ignore:
+      - "benchmarks/**"
+      - "doc/**"
+      - "docs/**"
+      - "**.md"
+      - "dev/changelog/*.md"
+      - "native/core/benches/**"
+      - "native/spark-expr/benches/**"
+      - "spark/src/main/scala/org/apache/comet/GenerateDocs.scala"
+      - "spark-integration/**"
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+env:
+  RUST_VERSION: stable
+  RUST_BACKTRACE: 1
+  # Force GNU ld on Linux to match the rest of Comet's CI (rust-lld can't
+  # resolve -ljvm against the Zulu JDK layout installed by setup-java).
+  RUSTFLAGS: "-Clink-arg=-fuse-ld=bfd"
+
+jobs:
+  delta-build-gate:
+    name: Build-gate verification (default builds exclude Delta)
+    runs-on: ubuntu-24.04
+    container:
+      image: amd64/rust
+    env:
+      SPARK_LOCAL_IP: localhost
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Setup Rust & Java toolchain
+        uses: ./.github/actions/setup-builder
+        with:
+          rust-version: ${{ env.RUST_VERSION }}
+          jdk-version: 17
+
+      - name: Run dev/verify-contrib-delta-gate.sh
+        run: |
+          dev/verify-contrib-delta-gate.sh