ci: add cross-platform build

Author: sbinet

.github/workflows/ci.yml

@@ -40,10 +40,19 @@ jobs:
     - name: Checkout code
       uses: actions/checkout@v2
 
+    - name: Install Linux packages
+      if: matrix.platform == 'ubuntu-latest'
+      run: |
+        sudo apt-get update
+        sudo apt-get install -qq pkg-config gcc-arm-linux-gnueabihf
+
     - name: Build-Linux-32b-arm
       if: matrix.platform == 'ubuntu-latest'
       run: |
-        GOARCH=arm   go install -v ./...
+        GOARCH=arm CGO_ENABLED=1 \
+            CC=arm-linux-gnueabihf-gcc \
+            CC_FOR_TARGET=arm-linux-gnueabihf-gcc \
+            go install -v ./...
     - name: Build-Linux-64b
       if: matrix.platform == 'ubuntu-latest'
       run: |