ci-basic.yml: test both with and without nu7/tx_v6 flags using a matrix

Author: dmidem

.github/workflows/ci-basic.yml

@@ -7,6 +7,12 @@ jobs:
   test:
     runs-on: ubuntu-latest
 
+    strategy:
+      matrix:
+        nu7:
+          - true
+          - false
+
     env:
       # Use system-installed RocksDB library instead of building from scratch
       ROCKSDB_LIB_DIR: /usr/lib
@@ -33,10 +39,24 @@ jobs:
         run: sudo apt-get update && sudo apt-get install -y protobuf-compiler librocksdb-dev
       - name: Install formatting & linting tools
         run: rustup component add rustfmt clippy
-      - name: Run tests
-        run: timeout --preserve-status 1h cargo test --verbose --locked
+
       - name: Verify working directory is clean
         run: git diff --exit-code
+
+      - name: Strip nu7/tx_v6 flags from config
+        if: ${{ !matrix.nu7 }}
+        run: |
+          python3 - <<'EOF'
+          import re
+          cfg = open('.cargo/config.toml').read()
+          # Remove tx_v6 and nu7 flags along with their preceding comments
+          cfg = re.sub(r'[ \t]*#[^\n]*tx_v6[^\n]*\n[ \t]*"--cfg",[^\n]*tx_v6[^\n]*\n', '', cfg)
+          cfg = re.sub(r'[ \t]*#[^\n]*nu7[^\n]*\n[ \t]*"--cfg",[^\n]*nu7[^\n]*\n', '', cfg)
+          open('.cargo/config.toml', 'w').write(cfg)
+          EOF
+
+      - name: Run tests
+        run: timeout --preserve-status 1h cargo test --verbose --locked
       - name: Run doc check
         run: cargo doc --workspace --no-deps --all-features --document-private-items --locked
       - name: Run format check