--- a/setup.py	Tue Aug 11 09:04:02 2009 +0200
+++ b/setup.py	Sun Oct 18 14:35:36 2009 +0200
@@ -97,7 +97,21 @@
 except ImportError:
     pass
 
-version = None
+def runcmd(cmd):
+    p = subprocess.Popen(cmd, stdout=subprocess.PIPE,
+                         stderr=subprocess.PIPE, env=env)
+    out, err = p.communicate()
+    # If root is executing setup.py, but the repository is owned by
+    # another user (as in "sudo python setup.py install") we will get
+    # trust warnings since the .hg/hgrc file is untrusted. That is
+    # fine, we don't want to load it anyway.
+    err = [e for e in err.splitlines()
+           if not e.startswith('Not trusting file')]
+    if err:
+        return ''
+    return out
+
+version = ''
 
 if os.path.isdir('.hg'):
     # Execute hg out of this directory with a custom environment which
@@ -113,34 +127,28 @@
         # error 0xc0150004. See: http://bugs.python.org/issue3440
         env['SystemRoot'] = os.environ['SystemRoot']
     cmd = [sys.executable, 'hg', 'id', '-i', '-t']
-
-    p = subprocess.Popen(cmd, stdout=subprocess.PIPE,
-                         stderr=subprocess.PIPE, env=env)
-    out, err = p.communicate()
-
-    # If root is executing setup.py, but the repository is owned by
-    # another user (as in "sudo python setup.py install") we will get
-    # trust warnings since the .hg/hgrc file is untrusted. That is
-    # fine, we don't want to load it anyway.
-    err = [e for e in err.splitlines()
-           if not e.startswith('Not trusting file')]
-    if err:
-        sys.stderr.write('warning: could not establish Mercurial '
-                         'version:\n%s\n' % '\n'.join(err))
+    l = runcmd(cmd).split()
+    while len(l) > 1 and l[-1][0].isalpha(): # remove non-numbered tags
+        l.pop()
+    if len(l) > 1: # tag found
+        version = l[-1]
+        if l[0].endswith('+'): # propagate the dirty status to the tag
+            version += '+'
+    elif len(l) == 1: # no tag found
+        cmd = [sys.executable, 'hg', 'parents', '--template',
+               '{latesttag}+{latesttagdistance}-']
+        version = runcmd(cmd) + l[0]
+    if version.endswith('+'):
+        version += time.strftime('%Y%m%d')
+elif os.path.exists('.hg_archival.txt'):
+    kw = dict([t.strip() for t in l.split(':', 1)]
+              for l in open('.hg_archival.txt'))
+    if 'tag' in kw:
+        version =  kw['tag']
+    elif 'latesttag' in kw:
+        version = '%(latesttag)s+%(latesttagdistance)s-%(node).12s' % kw
     else:
-        l = out.split()
-        while len(l) > 1 and l[-1][0].isalpha(): # remove non-numbered tags
-            l.pop()
-        if l:
-            version = l[-1] # latest tag or revision number
-            if version.endswith('+'):
-                version += time.strftime('%Y%m%d')
-elif os.path.exists('.hg_archival.txt'):
-    hgarchival = open('.hg_archival.txt')
-    for line in hgarchival:
-        if line.startswith('node:'):
-            version = line.split(':')[1].strip()[:12]
-            break
+        version = kw.get('node', '')[:12]
 
 if version:
     f = open("mercurial/__version__.py", "w")