issue-sl-setup  OS X Installer: readline module broken

            Changes for Issue6877 to enable the readline module to use the
            native OS X editline library instead of GNU readline introduce
            a problem for OS X installer builds or other builds using
            MACOSX_DEPLOYMENT_TARGET.  The test in setup.py to determine
            whether to search for a non-system library is based solely
            on the OS level of the build system and not the minimum
            deployment target level.  Without this patch to setup.py,
            10.3- or 10.4-targeted installer builds on 10.5 or 10.6
            will fail to search for the installer-supplied GNU readline
            *and* will be dynamically linked with the crippled
            10.4u SDK version of editline, thereby causing the readline
            module to crash on all levels of OS X.
            The patch also corrects a incorrect version test in setup.py
            that causes builds on 10.6 to be flooded with OS X deprecation
            warnings.

APPLIES     py3k, trunk, 2.6

NOTE        issue-sl-setup-py3k.txt   (this file)   py3k
            issue-sl-setup-trunk.txt                trunk
            issue-sl-setup-26.txt                   2.6

diff -r 593745b20300 setup.py
--- setup.py	Thu Mar 04 23:30:46 2010 -0800
+++ setup.py	Fri Mar 05 00:52:06 2010 -0800
@@ -492,6 +492,9 @@
         do_readline = self.compiler_obj.find_library_file(lib_dirs, 'readline')
         if platform == 'darwin':
             os_release = int(os.uname()[2].split('.')[0])
+            dep_target = sysconfig.get_config_var('MACOSX_DEPLOYMENT_TARGET')
+            if dep_target and dep_target.split('.') < ['10', '5']:
+                os_release = 8
             if os_release < 9:
                 # MacOSX 10.4 has a broken readline. Don't try to build
                 # the readline module unless the user has installed a fixed