Fixed #5941: added ARFLAGS for the archiver command.
diff --git a/Lib/distutils/sysconfig.py b/Lib/distutils/sysconfig.py
index 56cb861..099e058 100644
--- a/Lib/distutils/sysconfig.py
+++ b/Lib/distutils/sysconfig.py
@@ -165,9 +165,9 @@
     varies across Unices and is stored in Python's Makefile.
     """
     if compiler.compiler_type == "unix":
-        (cc, cxx, opt, cflags, ccshared, ldshared, so_ext, ar) = \
+        (cc, cxx, opt, cflags, ccshared, ldshared, so_ext, ar, ar_flags) = \
             get_config_vars('CC', 'CXX', 'OPT', 'CFLAGS',
-                            'CCSHARED', 'LDSHARED', 'SO', 'AR')
+                            'CCSHARED', 'LDSHARED', 'SO', 'AR', 'ARFLAGS')
 
         if 'CC' in os.environ:
             cc = os.environ['CC']
@@ -190,6 +190,10 @@
             ldshared = ldshared + ' ' + os.environ['CPPFLAGS']
         if 'AR' in os.environ:
             ar = os.environ['AR']
+        if 'ARFLAGS' in os.environ:
+            archiver = ar + ' ' + os.environ['ARFLAGS']
+        else:
+            archiver = ar + ' ' + ar_flags
 
         cc_cmd = cc + ' ' + cflags
         compiler.set_executables(
@@ -199,7 +203,7 @@
             compiler_cxx=cxx,
             linker_so=ldshared,
             linker_exe=cc,
-            archiver=ar)
+            archiver=archiver)
 
         compiler.shared_lib_extension = so_ext
 
diff --git a/Lib/distutils/tests/test_build_clib.py b/Lib/distutils/tests/test_build_clib.py
index 7374c49..3c6643f 100644
--- a/Lib/distutils/tests/test_build_clib.py
+++ b/Lib/distutils/tests/test_build_clib.py
@@ -1,9 +1,12 @@
 """Tests for distutils.command.build_clib."""
 import unittest
+import os
+import sys
 
 from distutils.command.build_clib import build_clib
 from distutils.errors import DistutilsSetupError
 from distutils.tests import support
+from distutils.spawn import find_executable
 
 class BuildCLibTestCase(support.TempdirManager,
                         support.LoggingSilencer,
@@ -97,6 +100,43 @@
         cmd.distribution.libraries = 'WONTWORK'
         self.assertRaises(DistutilsSetupError, cmd.finalize_options)
 
+    def test_run(self):
+        # can't test on windows
+        if sys.platform == 'win32':
+            return
+
+        pkg_dir, dist = self.create_dist()
+        cmd = build_clib(dist)
+
+        foo_c = os.path.join(pkg_dir, 'foo.c')
+        self.write_file(foo_c, 'int main(void) { return 1;}')
+        cmd.libraries = [('foo', {'sources': [foo_c]})]
+
+        build_temp = os.path.join(pkg_dir, 'build')
+        os.mkdir(build_temp)
+        cmd.build_temp = build_temp
+        cmd.build_clib = build_temp
+
+        # before we run the command, we want to make sure
+        # all commands are present on the system
+        # by creating a compiler and checking its executables
+        from distutils.ccompiler import new_compiler
+        from distutils.sysconfig import customize_compiler
+
+        compiler = new_compiler()
+        customize_compiler(compiler)
+        for ccmd in compiler.executables.values():
+            if ccmd is None:
+                continue
+            if find_executable(ccmd[0]) is None:
+                return # can't test
+
+        # this should work
+        cmd.run()
+
+        # let's check the result
+        self.assert_('libfoo.a' in os.listdir(build_temp))
+
 def test_suite():
     return unittest.makeSuite(BuildCLibTestCase)
 
diff --git a/Lib/distutils/tests/test_sysconfig.py b/Lib/distutils/tests/test_sysconfig.py
index dd17eb3..040dfcb 100644
--- a/Lib/distutils/tests/test_sysconfig.py
+++ b/Lib/distutils/tests/test_sysconfig.py
@@ -49,7 +49,8 @@
         if get_default_compiler() != 'unix':
             return
 
-        os.environ['AR'] = 'xxx'
+        os.environ['AR'] = 'my_ar'
+        os.environ['ARFLAGS'] = '-arflags'
 
         # make sure AR gets caught
         class compiler:
@@ -60,7 +61,7 @@
 
         comp = compiler()
         sysconfig.customize_compiler(comp)
-        self.assertEquals(comp.exes['archiver'], 'xxx')
+        self.assertEquals(comp.exes['archiver'], 'my_ar -arflags')
 
 
 def test_suite():