mkdir chroot
  cd chroot
  for lib in $(ldd ${executable} | grep -oE '/\S+'); do
    tgt="$(dirname ${lib})"
    mkdir -p .${tgt}
    cp ${lib} .${tgt}
  done
  mkdir -p .$(dirname ${executable})
  cp ${executable} .${executable}
  tar cf ../chroot-run-anywhere.tgz .

You're supposed to do this recursively for all the libs no?

Eg. Your App might just depend on libqt5gui.so but that libqt5gui.so might depend on some libxml etc...

Not to mention all the files from /usr/share etc... That your application might indirectly depend on.