3 files changed, 22 insertions, 0 deletions
diff --git a/Library/Homebrew/build.rb b/Library/Homebrew/build.rb
index 8a4267bac..e75a6841e 100755
--- a/Library/Homebrew/build.rb
+++ b/Library/Homebrew/build.rb
@@ -100,6 +100,8 @@ class Build
         Dependency.prune
       elsif dep.build? && dependent != f
         Dependency.prune
+      elsif dep.build?
+        Dependency.keep_but_prune_recursive_deps
       end
     end
   end
diff --git a/Library/Homebrew/dependency.rb b/Library/Homebrew/dependency.rb
index df22eed90..fda491b99 100644
--- a/Library/Homebrew/dependency.rb
+++ b/Library/Homebrew/dependency.rb
@@ -82,6 +82,8 @@ class Dependency
           next []
         when :skip
           expand(dep.to_formula, &block)
+        when :keep_but_prune_recursive_deps
+          [dep]
         else
           expand(dep.to_formula, &block) << dep
         end
@@ -110,6 +112,11 @@ class Dependency
       throw(:action, :skip)
     end
 
+    # Keep a dependency, but prune its dependencies
+    def keep_but_prune_recursive_deps
+      throw(:action, :keep_but_prune_recursive_deps)
+    end
+
     def merge_repeats(deps)
       grouped = deps.group_by(&:name)
 
diff --git a/Library/Homebrew/test/test_dependency_expansion.rb b/Library/Homebrew/test/test_dependency_expansion.rb
index 90d4dcc36..cf22b6170 100644
--- a/Library/Homebrew/test/test_dependency_expansion.rb
+++ b/Library/Homebrew/test/test_dependency_expansion.rb
@@ -95,4 +95,17 @@ class DependencyExpansionTests < Test::Unit::TestCase
 
     assert_equal [@bar, @baz], deps
   end
+
+  def test_keep_dep_but_prune_recursive_deps
+    f = stub(:deps => [
+      build_dep(:foo, [:build], [@bar]),
+      build_dep(:baz, [:build]),
+    ])
+
+    deps = Dependency.expand(f) do |dependent, dep|
+      Dependency.keep_but_prune_recursive_deps if dep.build?
+    end
+
+    assert_equal [@foo, @baz], deps
+  end
 end