This is a hack to work around <rdar://problem/6190548>, where the
CoreOS makefiles clobber LDFLAGS to an empty valie, defeating the
value calculated by configure.

Index: samba/source/Makefile.in
===================================================================
--- samba/source/Makefile.in.orig
+++ samba/source/Makefile.in
@@ -27,7 +27,7 @@ AR=@AR@
 LDSHFLAGS=@LDSHFLAGS@ @LDFLAGS@
 MODULE_EXPORTS=@MODULE_EXPORTS@
 WINBIND_NSS_LDSHFLAGS=@WINBIND_NSS_LDSHFLAGS@ @LDFLAGS@
-LDFLAGS=@PIE_LDFLAGS@ @LDFLAGS@
+override LDFLAGS=@PIE_LDFLAGS@ @LDFLAGS@
 AWK=@AWK@
 PICFLAG=@PICFLAG@
 DYNEXP=@DYNEXP@