From 2b9edf72bcabd5d745c1f73a07ce92f14242f512 Mon Sep 17 00:00:00 2001
From: Mike McQuaid <mike@mikemcquaid.com>
Date: Mon, 16 Nov 2020 13:21:23 +0000
Subject: [PATCH] unlink: unlink only keg-only versioned formulae.

As otherwise we unlink those that don't conflict e.g. `gcc@8` and
`gcc@9`.
---
 Library/Homebrew/unlink.rb | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Library/Homebrew/unlink.rb b/Library/Homebrew/unlink.rb
index bd265d5c5c9fa..47384433e3d55 100644
--- a/Library/Homebrew/unlink.rb
+++ b/Library/Homebrew/unlink.rb
@@ -8,6 +8,7 @@ module Unlink
 
     def unlink_versioned_formulae(formula, verbose: false)
       formula.versioned_formulae
+             .select(&:keg_only?)
              .select(&:linked?)
              .map(&:any_installed_keg)
              .compact