Homebrew

Versions

Now that homebrew/versions has been deprecated, homebrew/core supports multiple versions of formulae with a new naming format.

In homebrew/versions the formula for GCC 6 was named gcc6.rb and began with class Gcc6 < Formula. In homebrew/core this same formula is named gcc@6.rb and begins with class GccAT6 < Formula.

Acceptable versioned formulae

Homebrew’s versions are not intended to be used for any old versions you personally require for your project; formulae submitted should be expected to be used by a large number of people and still supported by their upstream projects.

Versioned formulae we include must meet the following standards:

• Versioned formulae should differ in major/minor (not patch) versions from the current stable release. This is because patch versions indicate bug or security updates and we want to ensure you apply security updates.
• Formulae that depend on versioned formulae must not depend on the same formulae at two different versions twice in their recursive dependencies. For example, if you depend on openssl@1.0 and foo, and foo depends on openssl then you must instead use openssl.
• Versioned formulae should only be linkable at the same time as their non-versioned counterpart if the upstream project provides support for it, e.g. using suffixed binaries. If this is not possible, use keg_only :versioned_formula to allow users to have multiple versions installed at once.

You should create your own tap for formulae you or your organisation wishes to control the versioning of or those that do not meet the above standards.