diff --git a/Library/Homebrew/cli/named_args.rb b/Library/Homebrew/cli/named_args.rb
index 89205c0297..3ba7e5fd7c 100644
--- a/Library/Homebrew/cli/named_args.rb
+++ b/Library/Homebrew/cli/named_args.rb
@@ -57,7 +57,7 @@ module Homebrew
           # Need to rescue before `*UnavailableError` (superclass of this)
           # The formula/cask was found, but there's a problem with its implementation
           raise
-        rescue NoSuchKegError, FormulaUnavailableError, Cask::CaskUnavailableError
+        rescue NoSuchKegError, FormulaUnavailableError, Cask::CaskUnavailableError, FormulaOrCaskUnavailableError
           ignore_unavailable ? [] : raise
         end.uniq.freeze
       end
@@ -91,8 +91,8 @@ module Homebrew
             when :keg
               resolve_keg(name)
             when :kegs
-              rack = Formulary.to_rack(name)
-              rack.directory? ? rack.subdirs.map { |d| Keg.new(d) } : []
+              _, kegs = resolve_kegs(name)
+              kegs
             else
               raise
             end
@@ -259,15 +259,21 @@ module Homebrew
       end
       private :spec
 
-      def resolve_keg(name)
+      def resolve_kegs(name)
         raise UsageError if name.blank?
 
         require "keg"
 
         rack = Formulary.to_rack(name.downcase)
 
-        dirs = rack.directory? ? rack.subdirs : []
-        raise NoSuchKegError, rack.basename if dirs.empty?
+        kegs = rack.directory? ? rack.subdirs.map { |d| Keg.new(d) } : []
+        raise NoSuchKegError, rack.basename if kegs.none?
+
+        [rack, kegs]
+      end
+
+      def resolve_keg(name)
+        rack, kegs = resolve_kegs(name)
 
         linked_keg_ref = HOMEBREW_LINKED_KEGS/rack.basename
         opt_prefix = HOMEBREW_PREFIX/"opt/#{rack.basename}"
@@ -275,7 +281,7 @@ module Homebrew
         begin
           return Keg.new(opt_prefix.resolved_path) if opt_prefix.symlink? && opt_prefix.directory?
           return Keg.new(linked_keg_ref.resolved_path) if linked_keg_ref.symlink? && linked_keg_ref.directory?
-          return Keg.new(dirs.first) if dirs.length == 1
+          return kegs.first if kegs.length == 1
 
           f = if name.include?("/") || File.exist?(name)
             Formulary.factory(name)