From a364ab0d0f5ac226ba9d5a519f2da8ab7a09a846 Mon Sep 17 00:00:00 2001
From: "Kelly (KT) Thompson" <kgt@lanl.gov>
Date: Wed, 30 Mar 2016 17:12:32 -0600
Subject: [PATCH] libpng depends on zlib.

---
 var/spack/repos/builtin/packages/libpng/package.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/var/spack/repos/builtin/packages/libpng/package.py b/var/spack/repos/builtin/packages/libpng/package.py
index e02b08663e..73c8c62341 100644
--- a/var/spack/repos/builtin/packages/libpng/package.py
+++ b/var/spack/repos/builtin/packages/libpng/package.py
@@ -9,6 +9,8 @@ class Libpng(Package):
     version('1.6.15', '829a256f3de9307731d4f52dc071916d')
     version('1.6.14', '2101b3de1d5f348925990f9aa8405660')
 
+    depends_on('zlib')
+
     def install(self, spec, prefix):
         configure("--prefix=%s" % prefix)
         make()