function in case of broken sysconfig. fix #1074

pip/pep425tags.py

@@ -1,6 +1,7 @@
 """Generate and work with PEP 425 Compatibility Tags."""
 
 import sys
+import warnings
 
 try:
     import sysconfig
@@ -25,10 +26,7 @@ def get_abbr_impl():
 
 def get_impl_ver():
     """Return implementation version."""
-    impl_ver = sysconfig.get_config_var("py_version_nodot")
-    if not impl_ver:
-        impl_ver = ''.join(map(str, sys.version_info[:2]))
-    return impl_ver
+    return ''.join(map(str, sys.version_info[:2]))
 
 
 def get_platform():
@@ -58,7 +56,12 @@ def get_supported(versions=None, noarch=False):
 
     abis = []
 
-    soabi = sysconfig.get_config_var('SOABI')
+    try:
+        soabi = sysconfig.get_config_var('SOABI')
+    except IOError as e: # Issue #1074
+        warnings.warn("{0}".format(e), RuntimeWarning)
+        soabi = None
+
     if soabi and soabi.startswith('cpython-'):
         abis[0:0] = ['cp' + soabi.split('-', 1)[-1]]
 
@@ -74,7 +77,7 @@ def get_supported(versions=None, noarch=False):
 
     if not noarch:
         arch = get_platform()
-    
+
         # Current version, current API (built specifically for our Python):
         for abi in abis:
             supported.append(('%s%s' % (impl, versions[0]), abi, arch))

tests/unit/test_wheel.py

@@ -150,12 +150,27 @@ def test_unpack_wheel_no_flatten(self):
         finally:
             rmtree(tmpdir)
             pass
-        
+
     def test_purelib_platlib(self):
         """
         Test the "wheel is purelib/platlib" code.
         """
         packages =  [("pure_wheel", "data/packages/pure_wheel-1.7", True),
-                     ("plat_wheel", "data/packages/plat_wheel-1.7", False)]        
+                     ("plat_wheel", "data/packages/plat_wheel-1.7", False)]
         for name, path, expected in packages:
             assert wheel.root_is_purelib(name, path) == expected
+
+class TestPEP425Tags(object):
+
+    def test_broken_sysconfig(self):
+        """
+        Test that pep425tags still works when sysconfig is broken.
+        Can be a problem on Python 2.7
+        Issue #1074.
+        """
+        import pip.pep425tags
+        def raises_ioerror(var):
+            raise IOError("I have the wrong path!")
+        with patch('pip.pep425tags.sysconfig.get_config_var', raises_ioerror):
+            assert len(pip.pep425tags.get_supported())
+