Unrecognized runtime "julia"; defaulting to "python3"

Question

I am trying to run the Julia template in Google Colab, but the first code block throws the following warning:

Unrecognized runtime "julia"; defaulting to "python3"

Google search didn't help. Any ideas?

Answer 1

Ignore the popup Unrecognized runtime "julia"; defaulting to "python3".

When you start, it opens a connection to a machine. julia is not installed on the machine. The first cell starts with '%%shell' to tell jupyter to feed the rest of the cell to the command 'shell'. The rest of the first cell are a series of shell commands that install julia.

This script that installs julia can take a while. When I just tried it, it ran for over 4 minutes. It has several "Installing ..." progress messages, but 3:30 of the wait was after it said "Installing Julia package Plots...". Eventually the output (white area below the gray cell that starts with '%%shell') should say something like the text that was there before it started:

Installing Julia 1.7.1 on the current Colab Runtime...
2022-05-12 01:19:55 URL:https://julialang-s3.julialang.org/bin/linux/x64/1.7/julia-1.7.1-linux-x86_64.tar.gz [123374573/123374573] -> "/tmp/julia.tar.gz" [1]
Installing Julia package IJulia...
Installing Julia package BenchmarkTools...
Installing Julia package Plots...
   (long delay here)
Installing IJulia kernel...
[ Info: Installing julia kernelspec in /root/.local/share/jupyter/kernels/julia-1.7
Successfully installed julia version 1.7.1!
Please reload this page (press Ctrl+R, ?+R, or the F5 key) then
jump to the 'Checking the Installation' section.

If you've waited much longer than 5 minutes and it hasn't completed, maybe try disconnecting (menu "Runtime" > "Disconnect and delete runtime"), refresh, and start the first cell again.

Answer 2

Ran into the same issue. Found this on Julia's discourse forum (https://discourse.julialang.org/t/how-to-run-julia-in-google-colab/43169)