fix

drone.yml

         tar -xf "$${PKG_RELEASE_DIR}/$${PKG_DEB_ARCHIVE}" -C "$${PKG_BUILD_DIR}" --strip 1 &&
         cd "$${PKG_BUILD_DIR}" &&
         export MAKEFLAGS="$${MAKEFLAGS}" &&
-        case $${ARCH} in 
+        case $${PKG_ARCH} in 
           amd64) PREFIX="" ;;
           armhf) PREFIX="arm-linux-gnueabihf-" ;;
         esac &&