  * package browser-targeted code when needed node module is in Debian:
    esm
  * package documentation when needed node module is in Debian:
    vuepress
  * check more of testsuite when needed node modules are in Debian:
    esm node-mysticatea-eslint-plugin nyc
  * improve generated source maps when needed node module is in Debian:
    rollup-plugin-sourcemaps
