From b1c031d26b0e94570511acfdb0dfb8a43f0f6e58 Mon Sep 17 00:00:00 2001
From: "Tim D. Smith" <git@tim-smith.us>
Date: Mon, 4 May 2015 22:15:19 -0700
Subject: [PATCH] Don't explicitly link python on darwin

Passing -undefined dynamic_lookup to the linker (instead of -lpython or
-framework Python) permits undefined symbols in shared libraries on OS
X. This allows a module to be linked against one Python framework and
imported from another.
---
 src/tools/python.jam | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/src/tools/python.jam b/src/tools/python.jam
index 1a41a1e86..90377eaae 100644
--- a/src/tools/python.jam
+++ b/src/tools/python.jam
@@ -962,16 +962,18 @@ local rule configure ( version ? : cmd-or-prefix ? : includes * : libraries ? :
     # symbols. If we linked to libpython, we would get duplicate symbols. So
     # declare two targets -- one for building extensions and another for
     # embedding.
-    #
-    # Unlike most *nix systems, Mac OS X's linker does not permit undefined
-    # symbols when linking a shared library. So, we still need to link against
-    # the Python framework, even when building extensions. Note that framework
-    # builds of Python always use shared libraries, so we do not need to worry
-    # about duplicate Python symbols.
-    if $(target-os) in windows cygwin darwin
+    if $(target-os) in windows cygwin
     {
         alias python_for_extensions : python : $(target-requirements) ;
     }
+    else if $(target-os) = darwin {
+        alias python_for_extensions
+            :
+            : $(target-requirements)
+            :
+            : $(usage-requirements) <linkflags>"-undefined dynamic_lookup"
+            ;
+    }
     # On AIX we need Python extensions and Boost.Python to import symbols from
     # the Python interpreter. Dynamic libraries opened with dlopen() do not
     # inherit the symbols from the Python interpreter.