what's difference between installing fastlane using homebrew cask, gem install and prepackaged

Question

fastlane docs suggest 3 ways of installation. What is the difference between using homebrew, gem install and downloading the prepackaged fastlane?

Answer 1

fastlane is a Ruby Gem. The following different installation methods are available:

Gem

Running gem install fastlane and/or including gem 'fastlane in a Gemfile and running bundle install install fastlane as a standard RubyGem.

Pros:

Works like any other RubyGem.

Cons:

Ruby version management. Sometimes system libraries and outdated dependencies or Ruby versions can get in the way of an easy installation process. (All the problems you may suffer from with any other gem.)

Caveat:

These issues can largely be taken care of by using a Ruby version management tool such as rbenv or rvm.

packaged-fastlane

This is a precompiled and self-contained version of Ruby with fastlane and it's dependencies (i.e. SSL) already installed.

Pros:

Does not rely on managing your own ruby version. Can be installed by running a script in the download and therefor does not require any prior knowledge about installing RubyGems.

Cons:

Some fastlane plugins and actions, that require native ruby extensions fail to build (there is an issue open about it, https://github.com/fastlane/fastlane/issues/8431#issuecomment-284415759 - however no fix is yet released).

Homebrew Cask

This is the exact same package as packaged-fastlane (mentioned above) but is distributed via Homebrew Cask and can be installed by running brew cask install fastlane

My recommendation

From support point of view, I strongly encourage users to use either the Homebrew or packaged-fastlane version, as it puts aside most of the system related issues you may stumble upon with RubyGems.

I personally use rvm and the gem version.

I am a fastlane core contributor.

edit: There is even a 4th variation, that is installed via the "Fabric" app for macOS - this version is largely the same as packaged-fastlane, it just lives in a different directory on disk.