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Joseph Kain

Professional Software Engineer learning Elixir.

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Installing multiple Elixir versions with Kiex

I like to try out different versions of Elixir including release candidates . This can be especially useful when I want to try out new features and write about them before the features make it into an official Elixir release. An example of this would be last month’s post on the Elixir’s new Special form “with”

The tool I use to manage multiple versions of Elixir is Kiex.

Using Kiex

Kiex’s documentation is quite good and you should refer to it for the basic installation.

The commands I use most frequently are:

  • kiex list known - to list all the Elixir versions Kiex knows about:
  • kiex install <version> to install Elixir version <version> on my system.
  • kiex use <version> to setup my current shell to use Elixir version <version>.

So for example, right now the known versions are:

kiex list known
Getting the available releases from https://github.com/elixir-lang/elixir/releases

  Known Elixir releases:
     1.2.1
     1.2.0
     1.2.0-rc.1
     1.2.0-rc.0
     1.1.1
     1.1.0
     1.1.0-rc.0
     0.9.3
     0.9.2
     0.9.1
     0.9.0
     0.8.3
     0.8.2
     0.8.1
     0.8.0
     0.7.2
     1.0.5
     1.0.4
     1.0.3
     1.0.2
     1.0.1
     1.0.0
     1.0.0-rc2
     1.0.0-rc1
     0.15.1
     0.15.0
     0.14.3
     0.14.2
     0.14.1
     0.14.0

There are plenty of versions to choose from including release candidates. And, Elixir 1.2.1 was released yesterday! I’ll install it like this:

$ kiex install 1.2.1
Switched to branch 'master'
Your branch is behind 'origin/master' by 289 commits, and can be fast-forwarded.
  (use "git pull" to update your local branch)
remote: Counting objects: 394, done.
remote: Compressing objects: 100% (47/47), done.
remote: Total 394 (delta 202), reused 183 (delta 183), pack-reused 162
Receiving objects: 100% (394/394), 123.77 KiB | 0 bytes/s, done.
Resolving deltas: 100% (245/245), completed with 76 local objects.
From https://github.com/elixir-lang/elixir
   ad03436..a43e6fc  master     -> origin/master
   bcc92cc..a3d88dc  v1.2       -> origin/v1.2
 * [new tag]         v1.2.1     -> v1.2.1
Switched to a new branch 'v1.2.1'
From https://github.com/elixir-lang/elixir
 * tag               v1.2.1     -> FETCH_HEAD
Already up-to-date.
cd lib/elixir && "/Users/jkain/.kiex/builds/elixir-git/rebar" clean
==> elixir (clean)
...
Installed Elixir version 1.2.1
Load with:
           kiex use 1.2.1
or load the elixir environment file with:
   source $HOME/.kiex/elixirs/elixir-1.2.1.env

Now that it’s installed I can set up my shell to run it like this:

$ kiex use 1.2.1
Using 1.2.1
$ iex
Erlang/OTP 18 [erts-7.2] [source-e6dd627] [64-bit] [smp:8:8] [async-threads:10] [hipe] [kernel-poll:false]

Interactive Elixir (1.2.1) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)>

Bash Prompt

I like to be able to quickly tell which version of Elixir I’m using so I include the version number in my Bash prompt. Kiex is kind enough to set the environment variable ELIXIR_VERSION. I can use that variable in my prompt like this:

RED="\[\033[0;31m\]"
LIGHT_BLUE="\[\033[1;34m\]"
DEFAULT="\[\033[0m\]"

function ex_version {
  if [ -n "$ELIXIR_VERSION" ]; then
    echo ":ex-$ELIXIR_VERSION"
  fi
}

PS1="${RED}jkain-mbp${LIGHT_BLUE}\$(ex_version)${DEFAULT} \w\n$ "

And this is what my prompt looks like:

My bash prompt

Conclusion

This was just a brief post to describe how I make use of Kiex and what you can do with it. I hope you’ve found this helpful.

Installing multiple Elixir versions with Kiex was published on .