Ruby

cd /Users/christopher/.rbenv/plugins/ruby-build && git pull && cd -

ChristophersMBP:bin christopher$ rbenv install 2.6.1

ruby-build: definition not found: 2.6.1

See all available versions with `rbenv install --list'.

If the version you need is missing, try upgrading ruby-build:

  cd /Users/christopher/.rbenv/plugins/ruby-build && git pull && cd -

ChristophersMBP:bin christopher$ cd /Users/christopher/.rbenv/plugins/ruby-build && git pull && cd -

remote: Enumerating objects: 280, done.

remote: Counting objects: 100% (280/280), done.

remote: Compressing objects: 100% (17/17), done.

remote: Total 423 (delta 261), reused 276 (delta 259), pack-reused 143

Receiving objects: 100% (423/423), 110.66 KiB | 7.90 MiB/s, done.

Resolving deltas: 100% (312/312), completed with 64 local objects.

From https://github.com/rbenv/ruby-build

   648fc99..ca85eba  master     -> origin/master

 * [new tag]         v20190423  -> v20190423

 * [new tag]         v20181207  -> v20181207

 * [new tag]         v20181225  -> v20181225

 * [new tag]         v20190130  -> v20190130

 * [new tag]         v20190314  -> v20190314

 * [new tag]         v20190320  -> v20190320

 * [new tag]         v20190401  -> v20190401

Updating 648fc99..ca85eba

Fast-forward

 bin/ruby-build