In the topic of updating JuMP, I think it is useful to understand environments.
When you start the REPL and install a package, it goes in your default environment, the one used if you do not select any specific environment.
However, it is useful to have many separate environments for each project of yours, so when you want to run some project you can immediately restore the exact same versions of the same packages used last time and the packages and versions of other projects do not disturb your current project.
So, I would suggest you to do the following.
- If you do not have a folder for this project of yours create one, and put your code inside.
- With the terminal/console inside the folder call
import Pkg; Pkg.activate(".") will change your environment from the default to your folder.
- You can check if you are in a new environment by using
Pkg.status() it will show no packages installed.
- Now you can install JuMP with
Pkg.add("JuMP"). Now two files named
Manifest.toml should have appeared in your folder, are they that save your environment, so do not mess with them unless you know what you are doing.
Pkg.status() to see JuMP installed and check which version was installed, it will probably be the
Pkg.add("PackageName") for the next package you need and check
Pkg.status() after, do it until you have all packages you want in the right version, or some package changes the version of JuMP to an older version. If this happens post the output of the
Pkg.status() before and after the downgrade here, so we can discover why this package is holding
Also, if you close the REPL and open it again, to go back to the environment you were using you need to either do
Pkg.activate(".") again. Or you can start Julia already in the right environment by using
julia --project=@.. In both cases your console need to already be inside the folder with the
toml files, or you need to replace the
. (the dot) in these commands by the path to the folder with the