How do you add Jupyter Notebook kernels for prior versions of Julia?

Question

I am using a Windows machine and trying to have Jupyter Notebook kernels for multiple versions of Julia (0.7.0 and 1.1.1) because package AWS does not support the latest version, but does support 0.7.0.

I had Julia 1.1.1 installed on my computer first and got something similar to the following error when I tried to install package AWS: https://github.com/JuliaLang/Pkg.jl/issues/792

Then I installed Julia 0.7.0 and was able to install AWS in the Julia 0.7.0 terminal with Pkg.add("AWS") with no problems.

In the Julia 0.7.0 terminal, I installed IJulia again with Pkg.add("IJulia") and restarted my Jupyter notebook instance. Now I'd like to use AWS via Jupyter notebook but when I create a new one, only Julia 1.1.1 appears.

I ended up having success by showing which kernels I had using jupyter kernelspec list in terminal, which showed where my other Julia kernel was located.

>>> jupyter kernelspec list
Available Kernels:
  julia-1.1    C:\Users\{%USERNAME%}\AppData\Roaming\jupyter\kernels\julia-1.1
  python3      C:\ProgramData\Anaconda3\share\jupyter\kernels\python3

1. I navigated to the file path listed after julia-1.1
2. Created a julia-0.7 folder in that same directory
3. Copied over contents from the julia-1.1 folder
4. Edited the kernel.json file by replacing every instance of julia-1.1.1 with julia-0.7.0

What I ended up having success with seems like a very rudimentary way to solve this problem. I'd like a more elegant way to achieve the same result, similar to when adding multiple kernels for different versions of Python. ( Using both Python 2.x and Python 3.x in IPython Notebook )

Please help, thank you!

Answer 1

You (probably) just need to Pkg.build("IJulia") on the second Julia version.

Since Julia 0.7 the package manager uses separate directories for each version of a package, meaning that, from the package managers perspective, the package is already installed, and no downloading or building is performed when you install the same version from a different Julia version. The package manager does not know, however, that IJulia needs to be rebuilt for this new Julia version. You can trigger the build manually by Pkg.build("IJulia") .