- Fixed: Buildout merged single-version requirements with

  version-range requirements in a way that caused it to think there
  wasn't a single-version requirement.  IOW, buildout throught that
  versions were being picked when they weren't.

CHANGES.rst

 Change History
 **************
 
+- Fixed: Buildout merged single-version requirements with
+  version-range requirements in a way that caused it to think there
+  wasn't a single-version requirement.  IOW, buildout throught that
+  versions were being picked when they weren't.
+
 2.3.0 (2014-12-14)
 ==================
 

src/zc/buildout/easy_install.py

@@ -1444,7 +1444,13 @@ def _constrained_requirement(constraint, requirement):
             constraint = constraint[2:]
         if constraint not in requirement:
             bad_constraint(constraint, requirement)
-        constraint = '==' + constraint
+
+        # Sigh, copied from Requirement.__str__
+        extras = ','.join(requirement.extras)
+        if extras:
+            extras = '[%s]' % extras
+        return pkg_resources.Requirement.parse(
+            "%s%s==%s" % (requirement.project_name, extras, constraint))
 
     if requirement.specs:
         return pkg_resources.Requirement.parse(

src/zc/buildout/repeatable.txt

@@ -163,6 +163,34 @@ We won't get output for the spam distribution, which we didn't pick,
 but we will get output for setuptools, which we didn't specify
 versions for.
 
+.. Edge case: version applied to range requirement:
+
+    >>> write('buildout.cfg',
+    ... '''
+    ... [buildout]
+    ... parts = foo
+    ... find-links = %s
+    ...
+    ... [versions]
+    ... spam = 1
+    ... eggs = 2.2
+    ...
+    ... [foo]
+    ... recipe = spam >0
+    ... ''' % join('recipe', 'dist'))
+
+    >>> print_(system(buildout+' -v'), end='')
+    Installing 'zc.buildout', 'setuptools'.
+    We have a develop egg: zc.buildout 1.0.0.
+    We have the best distribution that satisfies 'setuptools'.
+    Picked: setuptools = 0.6
+    Installing 'spam >0'.
+    We have the distribution that satisfies 'spam==1'.
+    Uninstalling foo.
+    Installing foo.
+    recipe v1
+
+
 You can request buildout to generate an error if it picks any
 versions:
 
@@ -204,7 +232,8 @@ We can name a version something else, if we wish, using the versions option:
     ... recipe = spam
     ... ''' % join('recipe', 'dist'))
     >>> print_(system(buildout), end='') # doctest: +ELLIPSIS
-    Updating foo.
+    Uninstalling foo.
+    Installing foo.
     recipe v1
 
 We can also disable checking versions:

src/zc/buildout/tests.py

@@ -2709,7 +2709,7 @@ def test_constrained_requirement():
     >>> examples = [
     ... # original, constraint, transformed
     ... ('x',        '1',        'x==1'),
-    ... ('x>1',      '2',        'x>1,==2'),
+    ... ('x>1',      '2',        'x==2'),
     ... ('x>3',      '2',        IncompatibleConstraintError),
     ... ('x>1',      '>2',       'x>1,>2'),
     ... ]