jupyter-client has to be installed but “jupyter kernelspec --version” exited with code 127

Question

I have already installed Jupyter notebook in my ubuntu 16.04 machine. In jupyter notebook there is by default python installed. Now I want to use R from jupyter notebook.

Answer 1

Assume that you have already run R in the terminal. You can first call library('IRkernel'), press Enter, then call installspec() or installspec(user=FALSE).

For me, simply calling IRkernel::installspec() will always raise the error you mentioned in your question. I don't know why what I did solved this problem on my centos server.