Added show-picked-versions option (default false).

Included: functionality (copy/pasted from buildout-versions) to
actually record and print the picked versions. For this, two new
class-level attributes on the Installer are added.

TODO: testing whether the printing of what required what also
works.

src/zc/buildout/buildout.py

@@ -136,6 +136,7 @@ _buildout_default_options = _annotate_section({
     'parts-directory': 'parts',
     'prefer-final': 'true',
     'python': 'buildout',
+    'show-picked-versions': 'false',
     'socket-timeout': '',
     'use-dependency-links': 'true',
     }, 'DEFAULT_VALUE')
@@ -243,7 +244,6 @@ class Buildout(DictMixin):
         #     file_name = buildout['buildout']['buildout_versions_file']
 
         # REINOUT: add 'update-versions-file' option.
-        # REINOUT: add a nice boolean show_picked_versions option.
 
         self._annotated = copy.deepcopy(data)
         self._raw = _unannotate(data)
@@ -334,6 +334,8 @@ class Buildout(DictMixin):
             bool_option(options, 'use-dependency-links'))
         zc.buildout.easy_install.allow_picked_versions(
                 bool_option(options, 'allow-picked-versions'))
+        zc.buildout.easy_install.show_picked_versions(
+                bool_option(options, 'show-picked-versions'))
 
         download_cache = options.get('download-cache')
         if download_cache:
@@ -646,42 +648,9 @@ class Buildout(DictMixin):
         elif (not installed_parts) and installed_exists:
             os.remove(self['buildout']['installed'])
 
-        # REINOUT Print picked versions here.
-        # self._print_picked_versions()
+        zc.buildout.easy_install.print_picked_versions()
         self._unload_extensions()
 
-    # def _print_picked_versions(self):
-    #     if picked_versions:
-    #         output = ['[versions]']
-    #         required_output = []
-    #         for dist_, version in sorted(picked_versions.items()):
-    #             if dist_ in required_by:
-    #                 required_output.append('')
-    #                 required_output.append('# Required by:')
-    #                 for req_ in sorted(required_by[dist_]):
-    #                     required_output.append('# '+req_)
-    #                 target = required_output
-    #             else:
-    #                 target = output
-    #             target.append("%s = %s" % (dist_, version))
-
-    #         output.extend(required_output)
-
-    #         print "Versions had to be automatically picked."
-    #         print "The following part definition lists the versions picked:"
-    #         print '\n'.join(output)
-    #         if file_name:
-    #             if os.path.exists(file_name):
-    #                 output[:1] = [
-    #                     '',
-    #                     '# Added by Buildout Versions at %s' % datetime.now(),
-    #                     ]
-    #             output.append('')
-    #             f = open(file_name,'a')
-    #             f.write('\n'.join(output))
-    #             f.close()
-    #             print "This information has been written to %r" % file_name
-
     def _update_installed(self, **buildout_options):
         installed = self['buildout']['installed']
         f = open(installed, 'a')

src/zc/buildout/buildout.txt

@@ -833,6 +833,8 @@ COMMAND_LINE_VALUE).
         DEFAULT_VALUE
     python= buildout
         DEFAULT_VALUE
+    show-picked-versions= false
+        DEFAULT_VALUE
     socket-timeout=
         DEFAULT_VALUE
     use-dependency-links= true
@@ -2373,6 +2375,7 @@ database is shown.
     parts-directory = /sample-buildout/parts
     prefer-final = true
     python = buildout
+    show-picked-versions = false
     socket-timeout =
     use-dependency-links = true
     verbosity = 20

src/zc/buildout/easy_install.py

@@ -69,9 +69,6 @@ buildout_and_distribute_path = [
 
 FILE_SCHEME = re.compile('file://', re.I).match
 
-# REINOUT: two new globals.
-# required_by = {}
-# picked_versions = {}  # This one could perhaps be local, on Installer?
 
 class AllowHostsPackageIndex(setuptools.package_index.PackageIndex):
     """Will allow urls that are local to the system.
@@ -124,11 +121,14 @@ _easy_install_cmd = 'from setuptools.command.easy_install import main; main()'
 class Installer:
 
     _versions = {}
+    _required_by = {}
+    _picked_versions = {}
     _download_cache = None
     _install_from_cache = False
     _prefer_final = True
     _use_dependency_links = True
     _allow_picked_versions = True
+    _show_picked_versions = False
 
     def __init__(self,
                  dest=None,
@@ -520,8 +520,7 @@ class Installer:
                 ):
                 logger.debug('Picked: %s = %s',
                              dist.project_name, dist.version)
-                # REINOUT: add the next line.
-                # picked_versions[dist.project_name] = dist.version
+                self._picked_versions[dist.project_name] = dist.version
 
                 if not self._allow_picked_versions:
                     raise zc.buildout.UserError(
@@ -732,6 +731,49 @@ def allow_picked_versions(setting=None):
         Installer._allow_picked_versions = bool(setting)
     return old
 
+def show_picked_versions(setting=None):
+    old = Installer._show_picked_versions
+    if setting is not None:
+        Installer._show_picked_versions = bool(setting)
+    return old
+
+def print_picked_versions():
+    if not Installer._show_picked_versions:
+        return
+    if not Installer._picked_versions:
+        # Don't print empty output.
+        return
+    output = ['[versions]']
+    required_output = []
+    for dist_, version in sorted(Installer._picked_versions.items()):
+        if dist_ in Installer._required_by:
+            required_output.append('')
+            required_output.append('# Required by:')
+            for req_ in sorted(Installer._required_by[dist_]):
+                required_output.append('# '+req_)
+            target = required_output
+        else:
+            target = output
+        target.append("%s = %s" % (dist_, version))
+
+    output.extend(required_output)
+
+    print "Versions had to be automatically picked."
+    print "The following part definition lists the versions picked:"
+    print '\n'.join(output)
+    # if file_name:
+    #     if os.path.exists(file_name):
+    #         output[:1] = [
+    #             '',
+    #             '# Added by Buildout Versions at %s' % datetime.now(),
+    #             ]
+    #     output.append('')
+    #     f = open(file_name,'a')
+    #     f.write('\n'.join(output))
+    #     f.close()
+    #     print "This information has been written to %r" % file_name
+
+
 def install(specs, dest,
             links=(), index=None,
             executable=sys.executable,
@@ -1240,26 +1282,25 @@ class MissingDistribution(zc.buildout.UserError):
         return "Couldn't find a distribution for %r." % str(req)
 
 def _log_requirement(ws, req):
-    if not logger.isEnabledFor(logging.DEBUG):
+    if (not logger.isEnabledFor(logging.DEBUG) and
+        not Installer._show_picked_versions):
         # Sorting the working set and iterating over it's requirements
-        # is expensive, so short cirtuit the work if it won't even be
+        # is expensive, so short circuit the work if it won't even be
         # logged.  When profiling a simple buildout with 10 parts with
         # identical and large working sets, this resulted in a
         # decrease of run time from 93.411 to 15.068 seconds, about a
         # 6 fold improvement.
         return
-    # REINOUT add extra check for 'allow-picked-versions=show'.
 
     ws = list(ws)
     ws.sort()
     for dist in ws:
         if req in dist.requires():
             logger.debug("  required by %s." % dist)
-            # REINOUT add the following lines.
-            # req_ = str(req)
-            # if req_ not in required_by:
-            #     required_by[req_] = set()
-            # required_by[req_].add(str(dist.as_requirement()))
+            req_ = str(req)
+            if req_ not in Installer._required_by:
+                Installer._required_by[req_] = set()
+            Installer._required_by[req_].add(str(dist.as_requirement()))
 
 def _fix_file_links(links):
     for link in links:

src/zc/buildout/repeatable.txt

@@ -228,6 +228,40 @@ We can also disable checking versions:
     Installing foo.
     recipe v2
 
+
+Easier reporting and managing of versions (new in buildout 2.0)
+---------------------------------------------------------------
+
+Since buildout 2.0, the functionality of the `buildout-versions
+<http://packages.python.org/buildout-versions/>`_ extension is part of
+buildout itself. This makes reporting and managing versions easier.
+
+If you set the ``show-picked-versions`` option, buildout will print
+versions it picked at the end of its run:
+
+    >>> write('buildout.cfg',
+    ... '''
+    ... [buildout]
+    ... parts = foo
+    ... find-links = %s
+    ... show-picked-versions = true
+    ...
+    ... [versions]
+    ...
+    ... [foo]
+    ... recipe = spam
+    ... ''' % join('recipe', 'dist'))
+    >>> print_(system(buildout), end='') # doctest: +ELLIPSIS
+    Updating foo.
+    recipe v2
+    Versions had to be automatically picked.
+    The following part definition lists the versions picked:
+    [versions]
+    distribute = 0.6.34
+    spam = 2
+
+
+
 Controlling the python version
 -------------------------------