try produce cross-compiled source packages

.github/workflows/release_cross_compiled.yaml

@@ -0,0 +1,104 @@
+# Workflow derived from https://github.com/r-lib/actions/tree/v2/examples
+# Need help debugging build failures? Start at https://github.com/r-lib/actions#where-to-find-help
+on:
+  push:
+    branches: [main]
+    tags:
+      - "**" # Push events to every tag including hierarchical tags like v1.0/beta
+  workflow_dispatch:
+
+name: Release
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+env:
+  RPOLARS_FULL_FEATURES: "true"
+  RPOLARS_CARGO_CLEAN_DEPS: "true"
+  RPOLARS_PROFILE: release-optimized
+
+jobs:
+  build:
+    runs-on: ${{ matrix.config.os }}
+
+    name: ${{ matrix.config.os }} (${{ matrix.config.r }})
+
+    permissions:
+      contents: write
+
+    strategy:
+      fail-fast: false
+      matrix:
+        config:
+          - {os: ubuntu-latest,  r: 'release', target: 'x86_64-apple-darwin'}
+          - {os: ubuntu-latest,  r: 'release', target: 'aarch64-apple-darwin'}
+
+    steps:
+      - uses: actions/checkout@v3
+
+      - uses: ./.github/actions/setup
+
+      - name: Fix path for Windows caching
+        if: runner.os == 'Windows'
+        shell: bash
+        run: echo "C:/Program Files/Git/usr/bin" >> $GITHUB_PATH
+
+      - uses: r-lib/actions/setup-pandoc@v2
+
+      - uses: r-lib/actions/setup-r@v2
+        with:
+          r-version: ${{ matrix.config.r }}
+          http-user-agent: ${{ matrix.config.http-user-agent }}
+          use-public-rspm: true
+          rtools-version: ${{ matrix.config.rtools-version }}
+          Ncpus: 2
+
+      - uses: r-lib/actions/setup-r-dependencies@v2
+        with:
+          extra-packages: any::rcmdcheck
+          needs: dev
+          pak-version: devel
+        env:
+          CI: false
+
+      - name: cross compile
+        run: |
+          pwd
+          rustup target add "${{ runner.target }}"
+          rustup default "${{ runner.target }}"
+          cargo build --lib --profile release-optimized --manifest-path=./src/rust/Cargo.toml
+          mv ./src/rust/target/release-optimized/libr_polars.a ./inst/
+          echo "${{ runner.os }}" > .inst/target.txt
+          cat .inst/target.txt
+          ls -l
+          ls ./inst/ -l
+        shell: bash
+
+      - name: build source (with object file)
+        run: |
+          runner_os <- readLines("./inst/target.txt")[1]
+          fn = devtools::build(vignettes = FALSE)
+          if (R.version$os != "mingw32") {
+            newfn = paste0(substr(fn,1,regexpr("_",fn)),"_cross_",runner_os,"_",R.version$platform,".",tools::file_ext(fn))
+            file.rename(fn, newfn)
+          } else {
+            file.rename(fn,"../polars.zip") #R expects specific windows binary filename
+          }
+        shell: Rscript {0}
+
+      - name: Release
+        uses: softprops/action-gh-release@v1
+        if: startsWith(github.ref, 'refs/tags/') && github.event_name != 'pull_request'
+        with:
+          files: |
+            ../polars_*
+            ../polars.zip
+
+      - name: print files
+        run: print(list.files("..",recursive = TRUE,full.names=TRUE))
+        shell: Rscript {0}
+
+      - name: print wd
+        run: print(getwd())
+        shell: Rscript {0}

src/Makevars

@@ -15,6 +15,12 @@ $(SHLIB): $(STATLIB)
 CARGOTMP = $(CURDIR)/.cargo
 
 $(STATLIB):
+	if [ -f "$(CURDIR)/../inst/libr_polars.a" ]; then \
+	  echo "refer directly to a precompiled object file + skip cargo build"; \
+	  mkdir -p ./rust/target/$(RPOLARS_PROFILE) ; \
+	  mv $(CURDIR)/../inst/libr_polars.a ./rust/target/$(RPOLARS_PROFILE)/libr_polars.a ; \
+	  exit 0 ; \
+	fi && \
 	if [ "true" != "true" ]; then \
 		export CARGO_HOME=$(CARGOTMP); \
 	fi && \