Ensure Docker is available on all platforms and fix Windows cross-compilation

- Use docker/setup-buildx-action for consistent Docker setup across all platforms
- Fix Windows rust-lld configuration by using full path instead of command name
- Make Docker-dependent tests fail explicitly when Docker is not available
- Add proper Docker availability check in integration tests

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

.github/workflows/ci.yml

@@ -45,14 +45,19 @@ jobs:
       run: |
         # On Windows, we'll use rust-lld as the linker for musl targets
         rustup component add llvm-tools-preview
+        # Find rust-lld location
+        $rustc_sysroot = rustc --print sysroot
+        $rust_lld = "$rustc_sysroot\lib\rustlib\x86_64-pc-windows-msvc\bin\rust-lld.exe"
+        Write-Host "rust-lld location: $rust_lld"
         # Create cargo config directory
         New-Item -ItemType Directory -Force -Path "$env:USERPROFILE\.cargo"
-        # Create config file
+        # Create config file with full path to rust-lld
         Add-Content -Path "$env:USERPROFILE\.cargo\config.toml" -Value "[target.x86_64-unknown-linux-musl]"
-        Add-Content -Path "$env:USERPROFILE\.cargo\config.toml" -Value 'linker = "rust-lld"'
+        Add-Content -Path "$env:USERPROFILE\.cargo\config.toml" -Value "linker = `"$rust_lld`""
-    - name: Set up Docker (Windows and macOS)
+    - name: Set up Docker for all platforms
-      if: matrix.os == 'windows-latest' || matrix.os == 'macos-latest'
+      uses: docker/setup-buildx-action@v3
-      uses: docker-practice/actions-setup-docker@v1
+      with:
+        install: true
     - name: Cache cargo registry
       uses: actions/cache@v4
       with:
@@ -68,7 +73,8 @@ jobs:
       with:
         path: target
         key: ${{ runner.os }}-cargo-build-target-${{ hashFiles('**/Cargo.lock') }}
-    - name: Verify cross-compilation setup
+    - name: Verify cross-compilation setup (Unix)
+      if: matrix.os != 'windows-latest'
       run: |
         echo "Installed targets:"
         rustup target list --installed
@@ -83,6 +89,26 @@ jobs:
         which rust-lld || echo "rust-lld not found"
         echo "Cargo config:"
         cat ~/.cargo/config.toml || echo "No cargo config found"
+    - name: Verify cross-compilation setup (Windows)
+      if: matrix.os == 'windows-latest'
+      shell: pwsh
+      run: |
+        Write-Host "Installed targets:"
+        rustup target list --installed
+        Write-Host "Cargo version:"
+        cargo --version
+        Write-Host "Rustc version:"
+        rustc --version
+        Write-Host "rust-lld location:"
+        $rustc_sysroot = rustc --print sysroot
+        $rust_lld = "$rustc_sysroot\lib\rustlib\x86_64-pc-windows-msvc\bin\rust-lld.exe"
+        if (Test-Path $rust_lld) {
+          Write-Host "$rust_lld exists"
+        } else {
+          Write-Host "$rust_lld not found"
+        }
+        Write-Host "Cargo config:"
+        Get-Content "$env:USERPROFILE\.cargo\config.toml" -ErrorAction SilentlyContinue || Write-Host "No cargo config found"
     - name: Build
       run: cargo build --verbose
     - name: Run unit tests

src/builder/mod.rs

@@ -50,10 +50,42 @@ impl RustBuilder {
         if cfg!(not(target_os = "linux")) && self.target.contains("linux") {
             // Check if we have a musl cross-compiler available
             if self.target.contains("x86_64-unknown-linux-musl") {
-                // On Windows, prefer rust-lld
+                // On Windows, use rust-lld with full path
                 if cfg!(target_os = "windows") {
+                    // Get the rust sysroot to find rust-lld
+                    let sysroot_output = Command::new("rustc")
+                        .arg("--print")
+                        .arg("sysroot")
+                        .output()
+                        .context("Failed to get rustc sysroot")?;
+
+                    if sysroot_output.status.success() {
+                        let sysroot = String::from_utf8_lossy(&sysroot_output.stdout)
+                            .trim()
+                            .to_string();
+                        let rust_lld = PathBuf::from(&sysroot)
+                            .join("lib")
+                            .join("rustlib")
+                            .join("x86_64-pc-windows-msvc")
+                            .join("bin")
+                            .join("rust-lld.exe");
+
+                        if rust_lld.exists() {
+                            cmd.env(
+                                "CARGO_TARGET_X86_64_UNKNOWN_LINUX_MUSL_LINKER",
+                                rust_lld.to_string_lossy().to_string(),
+                            );
+                            debug!("Using linker: {}", rust_lld.display());
+                        } else {
+                            // Fallback to just "rust-lld" and hope it's in PATH
                             cmd.env("CARGO_TARGET_X86_64_UNKNOWN_LINUX_MUSL_LINKER", "rust-lld");
-                    debug!("Using linker: rust-lld");
+                            debug!("Using linker: rust-lld (in PATH)");
+                        }
+                    } else {
+                        // Fallback to just "rust-lld"
+                        cmd.env("CARGO_TARGET_X86_64_UNKNOWN_LINUX_MUSL_LINKER", "rust-lld");
+                        debug!("Using linker: rust-lld (fallback)");
+                    }
                 } else {
                     // Try common linker names on other platforms
                     let linkers = if cfg!(target_os = "macos") {

tests/integration_test.rs

@@ -134,9 +134,16 @@ fn test_verbose_logging() -> Result<()> {
 #[cfg_attr(not(ci), ignore)] // Run in CI, but allow skipping locally
 fn test_full_build_and_run_workflow() -> Result<()> {
     // This test requires Docker
-    if StdCommand::new("docker").arg("version").output().is_err() {
+    let docker_check = StdCommand::new("docker").arg("version").output();
+    match docker_check {
+        Ok(output) if output.status.success() => {
+            // Docker is available, proceed with test
+        }
+        _ => {
+            // Docker not available or not working
             panic!("Docker is required for this test but is not available");
         }
+    }
 
     // Get the example project directory
     let example_dir = env::current_dir()?.join("example").join("hello-krust");