Fix compatibility with setuptools 39.

Fixes #8.

CHANGES.rst

@@ -1,8 +1,11 @@
 Changelog
 =========
 
-0.5.1 (unreleased)
-------------------
+1.0 (unreleased)
+----------------
+
+- Fix compatibility with setuptools 39 by using an API introduced
+  in setuptools 8.
 
 - Standardize namespace __init__
 

setup.py

@@ -50,7 +50,7 @@
     include_package_data=True,
     zip_safe=False,
     install_requires=[
-        'setuptools',
+        'setuptools >= 8',
     ],
     extras_require={
         'buildout': ['zc.buildout'],

src/z3c/checkversions/base.py

@@ -16,14 +16,10 @@
 from setuptools import package_index
 
 
-_final_parts = '*final-', '*final'
 def _final_version(parsed_version):
     """Function copied from zc.buildout.easy_install._final_version
     """
-    for part in parsed_version:
-        if (part[:1] == '*') and (part not in _final_parts):
-            return False
-    return True
+    return not parsed_version.is_prerelease
 
 
 class Checker(object):
@@ -105,10 +101,8 @@ def check(self, level=0):
                     continue
                 # trunk the version tuple to the first `level` elements
                 # (and remove *final and pad both to the level length)
-                trunked_current = [x for x in parsed_version[:level]
-                                   if not x.startswith('*')]
-                trunked_candidate = [x for x in dist.parsed_version[:level]
-                                     if not x.startswith('*')]
+                trunked_current = parsed_version.base_version.split('.')[:level]
+                trunked_candidate = dist.parsed_version.base_version.split('.')[:level]
                 while len(trunked_candidate) < level:
                     trunked_candidate.append('00000000')
                 while len(trunked_current) < level: