Merge pull request #8512 from Rylan12/disable-deprecation-reason

disable!, deprecate!: add reason

Library/Homebrew/formula.rb

@@ -1148,12 +1148,24 @@ class Formula
   # @return [Boolean]
   delegate deprecated?: :"self.class"
 
+  # The reason this {Formula} is deprecated.
+  # Returns `nil` if no reason is specified or the formula is not deprecated.
+  # @method deprecation_reason
+  # @return [String]
+  delegate deprecation_reason: :"self.class"
+
   # Whether this {Formula} is disabled (i.e. cannot be installed).
   # Defaults to false.
   # @method disabled?
   # @return [Boolean]
   delegate disabled?: :"self.class"
 
+  # The reason this {Formula} is disabled.
+  # Returns `nil` if no reason is specified or the formula is not disabled.
+  # @method disable_reason
+  # @return [String]
+  delegate disable_reason: :"self.class"
+
   def skip_cxxstdlib_check?
     false
   end
@@ -2766,9 +2778,14 @@ class Formula
     # Deprecates a {Formula} (on a given date, if provided) so a warning is
     # shown on each installation. If the date has not yet passed the formula
     # will not be deprecated.
-    def deprecate!(date: nil)
+    # <pre>deprecate! date: "2020-08-27", because: "it is no longer maintained"</pre>
+    def deprecate!(date: nil, because: nil)
+      # TODO: enable for next major/minor release
+      # odeprecated "`deprecate!` without a reason", "`deprecate! because: \"reason\"`" if because.blank?
+
       return if date.present? && Date.parse(date) > Date.today
 
+      @deprecation_reason = because if because.present?
       @deprecated = true
     end
 
@@ -2779,15 +2796,26 @@ class Formula
       @deprecated == true
     end
 
+    # The reason for deprecation of a {Formula}.
+    # Returns `nil` if no reason was provided or the formula is not deprecated.
+    # @return [String]
+    attr_reader :deprecation_reason
+
     # Disables a {Formula}  (on a given date, if provided) so it cannot be
     # installed. If the date has not yet passed the formula
     # will be deprecated instead of disabled.
-    def disable!(date: nil)
+    # <pre>disable! date: "2020-08-27", because: "it no longer builds"</pre>
+    def disable!(date: nil, because: nil)
+      # TODO: enable for next major/minor release
+      # odeprecated "`disable!` without a reason", "`disable! because: \"reason\"`" if because.blank?
+
       if date.present? && Date.parse(date) > Date.today
+        @deprecation_reason = because if because.present?
         @deprecated = true
         return
       end
 
+      @disable_reason = because if because.present?
       @disabled = true
     end
 
@@ -2798,6 +2826,11 @@ class Formula
       @disabled == true
     end
 
+    # The reason for a {Formula} is disabled.
+    # Returns `nil` if no reason was provided or the formula is not disabled.
+    # @return [String]
+    attr_reader :disable_reason
+
     # @private
     def link_overwrite(*paths)
       paths.flatten!

Library/Homebrew/formula_installer.rb

@@ -203,10 +203,18 @@ class FormulaInstaller
     raise FormulaInstallationAlreadyAttemptedError, formula if self.class.attempted.include?(formula)
 
     if formula.deprecated?
+      if formula.deprecation_reason.present?
+        opoo "#{formula.full_name} has been deprecated because #{formula.deprecation_reason}!"
+      else
         opoo "#{formula.full_name} has been deprecated!"
+      end
     elsif formula.disabled?
+      if formula.disable_reason.present?
+        odie "#{formula.full_name} has been disabled because #{formula.disable_reason}!"
+      else
         odie "#{formula.full_name} has been disabled!"
       end
+    end
 
     return if ignore_deps?