Issue #21187: Fix OS X installer fail-to-build with Xcode 5.1.
diff --git a/Mac/BuildScript/build-installer.py b/Mac/BuildScript/build-installer.py
index d4962ff..a67a606 100755
--- a/Mac/BuildScript/build-installer.py
+++ b/Mac/BuildScript/build-installer.py
@@ -867,7 +867,7 @@
                         ' -arch '.join(archList),
                         shellQuote(SDKPATH)[1:-1],
                         shellQuote(basedir)[1:-1],),
-                "LDFLAGS=-mmacosx-version-min=%s -syslibroot,%s -L%s/usr/local/lib -arch %s"%(
+                "LDFLAGS=-mmacosx-version-min=%s -isysroot %s -L%s/usr/local/lib -arch %s"%(
                     DEPTARGET,
                     shellQuote(SDKPATH)[1:-1],
                     shellQuote(basedir)[1:-1],