Handle broken symlinks in resolve_any_conflicts

Fixes Homebrew/homebrew#33328.

Library/Homebrew/keg.rb

@@ -328,11 +328,20 @@ class Keg
     return unless dst.symlink?
 
     src = dst.resolved_path
+
     # src itself may be a symlink, so check lstat to ensure we are dealing with
     # a directory, and not a symlink pointing at a directory (which needs to be
     # treated as a file). In other words, we only want to resolve one symlink.
-    # If it isn't a directory, make_relative_symlink will raise an exception.
+
-    if src.lstat.directory?
+    begin
+      stat = src.lstat
+    rescue Errno::ENOENT
+      # dst is a broken symlink, so remove it.
+      dst.unlink unless mode.dry_run
+      return
+    end
+
+    if stat.directory?
       keg = Keg.for(src)
       dst.unlink unless mode.dry_run
       keg.link_dir(src, mode) { :mkpath }

Library/Homebrew/test/test_keg.rb

@@ -239,4 +239,20 @@ class LinkTests < Homebrew::TestCase
     a.uninstall
     b.uninstall
   end
+
+  def test_removes_broken_symlinks_that_conflict_with_directories
+    a = HOMEBREW_CELLAR.join("a", "1.0")
+    a.join("lib", "foo").mkpath
+
+    keg = Keg.new(a)
+
+    link = HOMEBREW_PREFIX.join("lib", "foo")
+    link.parent.mkpath
+    link.make_symlink(@nonexistent)
+
+    keg.link
+  ensure
+    keg.unlink
+    keg.uninstall
+  end
 end