bundler: command not found

bundler: command not found means the bundle executable isn’t on your PATH — Bundler needs to be installed as a gem before you can use it.

What It Means

Bundler is a Ruby gem that manages application dependencies by reading a Gemfile and resolving compatible versions. Unlike gem, which comes bundled with Ruby, Bundler is a separate gem that must be installed explicitly. When you type bundle install and get “command not found”, it means the bundle executable isn’t on your PATH.

Why It Happens

• Bundler isn’t installed — it’s not bundled with Ruby by default in all setups.
• Bundler is installed for a different Ruby version (via rbenv or RVM) than the one currently active.
• The gem binaries directory isn’t in your PATH.
• You installed Bundler globally but your Bundler user directory isn’t on PATH.
• The bundler gem installation failed or was interrupted.

How to Fix It

Step 1: Install Bundler

This is the most common fix:

gem install bundler

If you get a permission error, you may need:

sudo gem install bundler  # Not recommended — use rbenv/RVM instead

Or with a version manager:

# With rbenv — gems install per Ruby version automatically
gem install bundler
rbenv rehash  # Make shims available

Step 2: Verify the installation

bundler --version
# Or
bundle --version

Both bundler and bundle commands should work.

Step 3: Check your PATH

If Bundler is installed but not found:

gem environment gemdir
# Example output: /home/user/.rbenv/versions/3.3.0/lib/ruby/gems/3.3.0

ls $(gem environment gemdir)/bin
# Check if 'bundle' and 'bundler' are there

If the gem bin directory isn’t in your PATH, add it:

echo 'export PATH="$PATH:$(ruby -e "puts Gem.bindir")"' >> ~/.bashrc
source ~/.bashrc

Step 4: Make sure you’re using the correct Ruby version

ruby --version
# If you switched Ruby versions, reinstall Bundler:
rbenv global 3.3.0
gem install bundler

Step 5: Run bundle install in your project

Once Bundler is available:

cd your-project
bundle install