Add :libltdl dep for libtool's libltdl

The :libtool dep is implicitly a build-time dep; :libltdl can be used
for software that uses the ltdl library at runtime.

1 files changed, 7 insertions, 2 deletions

diff --git a/Library/Homebrew/dependency_collector.rb b/Library/Homebrew/dependency_collector.rb
index e5da02429..2a40e1ad8 100644
--- a/Library/Homebrew/dependency_collector.rb
+++ b/Library/Homebrew/dependency_collector.rb
@@ -74,7 +74,7 @@ private
 
   def parse_symbol_spec spec, tag
     case spec
-    when :autoconf, :automake, :bsdmake, :libtool
+    when :autoconf, :automake, :bsdmake, :libtool, :libltdl
       # Xcode no longer provides autotools or some other build tools
       autotools_dep(spec, tag)
     when *X11Dependency::Proxy::PACKAGES
@@ -103,8 +103,13 @@ private
   end
 
   def autotools_dep(spec, tag)
+    case spec
+    when :libltdl then spec, tag = :libtool, Array(tag)
+    else tag = Array(tag) << :build
+    end
+
     unless MacOS::Xcode.provides_autotools?
-      Dependency.new(spec.to_s, [:build, *tag])
+      Dependency.new(spec.to_s, tag)
     end
   end
 end