ruby, gem, rbenv command not found

Question

I've been setting up some ruby dependencies throughout a day on my Lubuntu (18.04) in VM. ~~I installed ruby 2.4.0 and then installed rbenv and set 2.4.0 as global version to be used~~ (probably reverse order). Then I installed bundler and started installing dependencies for my Sinatra app. Since I needed some native extension I also installed libpq-dev via sudo apt-get install, installed pg gem and ran bundler again. And then I have

Command 'ruby' not found, but can be installed with:
sudo apt install ruby

Same with bundle or gem commands.

I can see that I have rbenv in /home/michalvantuch/.rbenv/bin/rbenv and also /home/michalvantuch/.rbenv/versions/2.4.0/.

My path:

/home/michalvantuch/.rbenv/plugins/ruby-build/bin:/home/michalvantuch/.rbenv/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games

My bash history:

bundle install
gem install pg -v '0.21.0' --source 'https://rubygems.org/'
vi /home/michalvantuch/.rbenv/versions/2.4.0/lib/ruby/gems/2.4.0/extensions/x86_64-linux/2.4.0-static/pg-0.21.0/mkmf.log
sudo apt-get install libpq-dev
gem install pg -v '0.21.0' --source 'https://rubygems.org/'
bundle install
gem list --local
cd /home/michalvantuch/.rbenv/bin/
ls -lah
C rbenv -> ../libexec/rbenv
cd rbenv -> ../libexec/rbenv
cd rbenv
cd ../libexec/
ls -lah
pwd
cd ..

I'm weary and not sure how to fix this. Did I mess up with the system privileges ?

Is that ordering correct? "I installed ruby" followed by "I installed rbenv"? What rubies does rbenv tell you are installed? — Marc Talbot
I have no output from rbenv, like it does nothing. You're right, I probably installed rbenv and then set ruby to 2.4.0. I remember it being set, but not installing. But then I'd expect the other commands to not work at all. — user2229608
The other commands work because you have a ruby installed. Install plugin that lets you install rubies, then use that to install 2.4.0, then you should be good to go. — Marc Talbot
I'm not sure I got this part ? Install plugin that lets you install rubies, then use that to install 2.4.0 — user2229608
rbenv doesn't by itself install rubies out of the box. Generally you need to install the github.com/rbenv/ruby-build#readme plugin, which will enable the rbenv install command. — Marc Talbot

Hariharan L Hariharan L · Accepted Answer · 2018-05-31T16:39:16

Complete setup commands for rbenv in linux machines Initial setup

git clone https://github.com/rbenv/rbenv.git ~/.rbenv
cd ~/.rbenv && src/configure && make -C src
echo 'export PATH="$HOME/.rbenv/bin:$PATH"' >> ~/.bashrc
source ~/.bashrc 
~/.rbenv/bin/rbenv init

check whether eval "$(rbenv init -)" is present in ~/.bashrc. If not present run the following command

echo 'eval "$(rbenv init -)"' >> ~/.bashrc

Then,

source ~/.bashrc
mkdir -p "$(rbenv root)"/plugins
git clone https://github.com/rbenv/ruby-build.git "$(rbenv root)"/plugins/ruby-build
source ~/.bashrc
rbenv rehash

Now, rbenv installed. Now install your ruby version ( change the version below to your version). And set that to global version. (Use latest stable version as global as it is a good practice. You can set local versions differently depending on your working project)

rbenv install 2.5.1
rbenv global 2.5.1

Finished.

ruby, gem, rbenv command not found

2 Answers