Merge pull request #327 from buildout/fix-326

Fixes #326

CHANGES.rst

@@ -4,7 +4,11 @@ Change History
 2.7.1 (unreleased)
 ==================
 
-- Nothing changed yet.
+- Fixed a bug introduced in 2.6.0:
+  zc.buildout and its dependeoncies were reported as picked even when
+  their versions were fixed in a ``versions`` section.  Worse, when the
+  ``update-versions-file`` option was used, the ``versions`` section was
+  updated needlessly on every run.
 
 
 2.7.0 (2017-01-30)

src/zc/buildout/easy_install.py

@@ -188,7 +188,8 @@ class Installer:
                  newest=True,
                  versions=None,
                  use_dependency_links=None,
-                 allow_hosts=('*',)
+                 allow_hosts=('*',),
+                 check_picked=True,
                  ):
         assert executable == sys.executable, (executable, sys.executable)
         self._dest = dest
@@ -218,6 +219,7 @@ class Installer:
         self._env = pkg_resources.Environment(path)
         self._index = _get_index(index, links, self._allow_hosts)
         self._requirements_and_constraints = []
+        self._check_picked = check_picked
 
         if versions is not None:
             self._versions = normalize_versions(versions)
@@ -558,8 +560,9 @@ class Installer:
                                                      self._links,
                                                      self._allow_hosts)
 
-        for dist in dists:
+        if self._check_picked:
             # Check whether we picked a version and, if we did, report it:
+            for dist in dists:
                 if not (
                     dist.precedence == pkg_resources.DEVELOP_DIST
                     or
@@ -573,7 +576,8 @@ class Installer:
 
                     if not self._allow_picked_versions:
                         raise zc.buildout.UserError(
-                        'Picked: %s = %s' % (dist.project_name, dist.version)
+                            'Picked: %s = %s' % (dist.project_name,
+                                                 dist.version)
                             )
 
         return dists
@@ -875,6 +879,7 @@ def install(specs, dest,
             use_dependency_links=None, allow_hosts=('*',),
             include_site_packages=None,
             allowed_eggs_from_site_packages=None,
+            check_picked=True,
             ):
     assert executable == sys.executable, (executable, sys.executable)
     assert include_site_packages is None
@@ -883,14 +888,16 @@ def install(specs, dest,
     installer = Installer(dest, links, index, sys.executable,
                           always_unzip, path,
                           newest, versions, use_dependency_links,
-                          allow_hosts=allow_hosts)
+                          allow_hosts=allow_hosts,
+                          check_picked=check_picked)
     return installer.install(specs, working_set)
 
-buildout_and_setuptools_dists = list(install(['zc.buildout'], None))
+buildout_and_setuptools_dists = list(install(['zc.buildout'], None,
+                                             check_picked=False))
 buildout_and_setuptools_path = [d.location
                                 for d in buildout_and_setuptools_dists]
 setuptools_path = [d.location
-                   for d in install(['setuptools'], None)]
+                   for d in install(['setuptools'], None, check_picked=False)]
 setuptools_pythonpath = os.pathsep.join(setuptools_path)
 
 def build(spec, dest, build_ext,

src/zc/buildout/repeatable.txt

@@ -420,10 +420,8 @@ The versions file now contains the extra pin:
 
 And re-running buildout doesn't report any picked versions anymore:
 
-    >>> print_(system(buildout), end='') # doctest: +ELLIPSIS
-    Updating foo.
-    recipe v2
-    ...
+    >>> 'picked' in system(buildout)
+    False
 
 If you've enabled ``update-versions-file`` but not ``show-picked-versions``,
 buildout will append the versions to your versions file anyway (without

src/zc/buildout/tests.py

@@ -3062,6 +3062,45 @@ def test_abi_tag_eggs():
     ...
     """
 
+def test_buildout_doesnt_keep_adding_itself_to_versions():
+    r"""
+    We were constantly writing to versions.cfg for buildout and setuptools
+
+    >>> write('buildout.cfg',
+    ... '''
+    ... [buildout]
+    ... parts =
+    ... extends = versions.cfg
+    ... show-picked-versions = true
+    ... update-versions-file = versions.cfg
+    ... extends = versions.cfg
+    ... ''')
+    >>> write('versions.cfg',
+    ... '''[versions]
+    ... ''')
+    >>> _ = system(join('bin', 'buildout'))
+    >>> with open('versions.cfg') as f:
+    ...     versions = f.read()
+    >>> _ = system(join('bin', 'buildout'))
+
+    On the first run, some pins were added:
+
+    >>> cat('versions.cfg') # doctest: +ELLIPSIS
+    [versions]
+    <BLANKLINE>
+    # Added by buildout...
+    setuptools = 34.0.3
+    ...
+    >>> _ = system(join('bin', 'buildout'))
+    >>> _ = system(join('bin', 'buildout'))
+
+    Subsequent runs didn't add additional text:
+
+    >>> with open('versions.cfg') as f:
+    ...     versions == f.read()
+    True
+    """
+
 if sys.platform == 'win32':
     del buildout_honors_umask # umask on dohs is academic