Warning message: package ‘ggplot2’ was built under R version 3.4.4

@mishabalyasin is correct, some of which I expressed in my response to the GitHub issue you opened re. same:

In the future, please take into account that we try to avoid cross-posting of active questions for this very reason— (roughly four hours ago, Misha and I both answered your question, not knowing that the other was doing so on a different platform).

That's not to say that issues won't be mentioned here on the community site— in fact, I know I've referred issues here, and vice-versa, many a question here in community have turned out to be bugs or feature requests reported or made in the appropriate GitHub repos. However, we ask that you avoid concurrently cross posting.

For more detail, see the FAQ below: