fix

drone.yml

         -cJvf "$${PKG_DEB_ARCHIVE}" .
 
       # https://wiki.debian.org/CrossCompiling#Building_with_dpkg-buildpackage
-    - PKG_BUILDHOST_ARCH="${DRONE_RUNNER_ARCH}" &&
+    - PKG_BUILDHOST_ARCH="amd64" &&
       PKG_SRC_ROOT="$(pwd)" &&
-      for PKG_ARCH in ${BUILD_ARCH} ; do cd "$${PKG_SRC_ROOT}" &&
+      for PKG_ARCH in $${BUILD_ARCH} ; do cd "$${PKG_SRC_ROOT}" &&
         PKG_RELEASE_ARCHIVE="$${PKG_NAME}_$${PKG_VERSION}_$${PKG_ARCH}.tar.xz" &&
         PKG_RELEASE_ARCHIVE_ROOT="$${PKG_NAME}-$${PKG_VERSION}" &&
         PKG_BUILD_DIR="build/$${PKG_ARCH}/$${PKG_ARCHIVE_ROOT}" &&
         tar -xf "$${PKG_DEB_ARCHIVE}" -C "$${PKG_ARCHIVE_ROOT}" --strip 1 &&
         cd "$${PKG_BUILD_DIR}" &&
-        export MAKEFLAGS="${MAKEFLAGS}" &&
+        export MAKEFLAGS="$${MAKEFLAGS}" &&
         make &&
         tar --exclude='./.*'
           --transform "s/$${PKG_DIST_DIR}/$${PKG_RELEASE_ARCHIVE_ROOT}/"