From e9ebc938e08686c8b5364dbd61827dc9d68589d5 Mon Sep 17 00:00:00 2001
From: Dane Springmeyer <dane@mapbox.com>
Date: Tue, 19 Jun 2018 17:21:50 -0700
Subject: [PATCH] [build] ensure we don't fail abruptly in
 BOOST_LIB_VERSION_FROM_HEADER is unknown

---
 SConstruct | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/SConstruct b/SConstruct
index 35a9afa1d..da31c1423 100644
--- a/SConstruct
+++ b/SConstruct
@@ -1597,8 +1597,8 @@ if not preconfigured:
         # around. See https://svn.boost.org/trac/boost/ticket/6779 for more
         # details.
         if not env['HOST']:
-            boost_version = [int(x) for x in env.get('BOOST_LIB_VERSION_FROM_HEADER').split('_')]
             if not conf.CheckBoostScopedEnum():
+                boost_version = [int(x) for x in env.get('BOOST_LIB_VERSION_FROM_HEADER').split('_') if x]
                 if boost_version < [1, 51]:
                     env.Append(CXXFLAGS = '-DBOOST_NO_SCOPED_ENUMS')
                 elif boost_version < [1, 57]: