Today I needed to execute a ruby gem executable with sudo. But, surprisingly, bash would tell me command not found for the gem that ran lovely without sudo.

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Gem bins are installed to /var/lib/gems/1.8/bin, which is not in sudo’s PATH. Unfortunately, you can’t change the path, since sudo for Ubuntu is compiled with the --with-secure-path option.

#Solution A: symlink the gems (if you need only some few gems)

• for each gem you need for sudo, run `ln -s /var/lib/gems/1.8/bin/gem_for_sudo /usr/local/bin/gem_for_sudo

#Solution B: update the path where gem install puts executables (if you need to execute many to all gems with sudo)

• move all the bins in /var/lib/gems/1.8/bin/ to /usr/local/bin/ (so gem will still be aware of them)
• edit or create ~/.gemrc and make sure there’s a line reading
  ^
  gem: --bindir /usr/local/bin

#Solution C: overwrite sudo’s secure path anyway

I discourage to do this:

• run sudo visudo
• add the line
  ^
  Defaults secure_path=: