Julia: Use an older version of a package

1
votes

I am really new to Julia and confused about using an old version of the SISL Vec package.

I am trying to setup ngsim_env and their instructions require you to use an older v0.1.0 of Vec. But, when I followed the instructions to install the Vec package and then checkout the v0.1.0 tag it didn't work.

Here's what I did

  1. $ julia ../build.jl for some package which includes this block

    packages = keys(Pkg.installed()) if !in("Vec", packages) Pkg.clone("https://github.com/tawheeler/Vec.jl.git") end

Note: This git URL actually goes to the SISL Vec page.

  1. cd ~/.julia/packages/Vec git fetch tags git checkout v0.1.0

  2. I did a bunch of other installations with many other packages. At some point I noticed that there is a package ~/.julia/dev/Vec and ~/.julia/packages/Vec. The one in dev has the correct v0.1.0 code and the one in packages has the newer wrong code. When I tried to use other packages that needed the older Vec they were throwing errors and the paths were to files in the packages directory.

  3. I tried Pkg.rm("Vec"). This did something to the project manifest. After nothing worked, every package would throw errors like KeyError: key "Vec" not found and Pkg.add("Vec") nor original Vec installation helped. I even tried removing both the Vec directories from ~/.julia but that didn't help.

I guess a big question is why does Julia put some packages into packages/ and others into dev/ and how to control which one's get used if the same package appears in both places like Vec is.

Would greatly appreciate any assistance, totally confused.

1
julia

1 Answers

2
votes

The dev command fetches a full clone of the package to ~/.julia/dev/

via the docs. The only things I have in my dev directory there are the ones I am developing on my own.

I think that triggered when you did a check out manually with git checkout. Accordingly:

to stop tracking a path and use the registered version again, use free

Try deleting the packages, and whipping mentions of Vec.jl from your manifest:

(v1.0) pkg> rm Vec
(v1.0) pkg> add https://github.com/tawheeler/[email protected]

In general, try using Pkg when possible, cause it does a lot of house keeping magic in the back

(Also, the repl interface with pkg makes everything easier, so hit ] from a blank julia> to get there. And a quick Pkg.status() or ] st will show you what youre tracking and whats in dev and what version you have pinned, etc.)