audit: flag use of "fails_with :llvm".

Also, add TODOs for deprecating this properly at a later point.

1 files changed, 4 insertions, 0 deletions

diff --git a/Library/Homebrew/dev-cmd/audit.rb b/Library/Homebrew/dev-cmd/audit.rb
index ee03c01ac..0112c524f 100644
--- a/Library/Homebrew/dev-cmd/audit.rb
+++ b/Library/Homebrew/dev-cmd/audit.rb
@@ -1000,6 +1000,10 @@ class FormulaAuditor
       problem "Use Language::Node for npm install args"
     end
 
+    if line.include?("fails_with :llvm")
+      problem "'fails_with :llvm' is now a no-op so should be removed"
+    end
+
     return unless @strict
 
     if line =~ /system ((["'])[^"' ]*(?:\s[^"' ]*)+\2)/