Refactored easy_install to use a subprocess. This will be necessary

to be able to use external python interpreters.

Wrote a missing test.

src/zc/buildout/easy_install.py

@@ -20,36 +20,13 @@ installed.
 $Id$
 """
 
-# XXX needs doctest
-
-import sys
-import setuptools.command.easy_install
-import pkg_resources
-import setuptools.package_index
-import distutils.dist
-import distutils.log
-
-def install(spec, dest, links=(), **kw):
-    index = setuptools.package_index.PackageIndex()
-    index.add_find_links(links)
-    easy = setuptools.command.easy_install.easy_install(
-        distutils.dist.Distribution(),
-        multi_version=True,
-        exclude_scripts=True,
-        sitepy_installed=True,
-        install_dir=dest,
-        outputs=[],
-        verbose = 0,
-        args = [spec],
-        find_links = links,
-        **kw
-        )
-    easy.finalize_options()
-
-    old_warn = distutils.log.warn
-    distutils.log.warn = lambda *a, **k: None
-
-    easy.easy_install(spec, deps=True)
-
-    distutils.log.warn = old_warn
-    
+import os, sys
+
+def install(spec, dest, links, python=sys.executable):
+    prefix = sys.exec_prefix + os.path.sep
+    path = os.pathsep.join([p for p in sys.path if not p.startswith(prefix)])
+    os.spawnle(
+        os.P_WAIT, python, python,
+        '-c', 'from setuptools.command.easy_install import main; main()',
+        '-mqxd', dest, '-f', ' '.join(links), spec,
+        dict(PYTHONPATH=path))

src/zc/buildout/easy_install.txt

+Minimal Python interface to easy_install
+========================================
+
+The easy_install module provides a minimal interface to the setuptools
+easy_install command.  This API is likely to grow, although I hope
+that it will ultimately be replaced by a setuptools-provided API.
+
+The easy_install module provides a single method, install.  The
+install function takes 3 arguments:
+
+- A setuptools requirement specification for a distribution to be
+  installed, 
+
+- A destination egg directory to install to and to satisfy
+  requirements from, and
+
+- a sequence of lications to look for distributions.
+
+For example, given the sample eggs:
+
+    >>> ls(sample_eggs)
+    -  demo-0.1-py2.3.egg
+    -  demo-0.2-py2.3.egg
+    -  demo-0.3-py2.3.egg
+    -  demoneeded-1.0-py2.3.egg
+
+let's make directory and install the demo egg to it:
+
+    >>> import tempfile
+    >>> dest = tempfile.mkdtemp()
+    >>> import zc.buildout.easy_install
+    >>> zc.buildout.easy_install.install('demo', dest, [sample_eggs])
+    >>> ls(dest)
+    -  demo-0.3-py2.3.egg
+    -  demoneeded-1.0-py2.3.egg
+

src/zc/buildout/tests.py

@@ -97,7 +97,7 @@ def test_suite():
                ])
             ),
         doctest.DocFileSuite(
-            'egglinker.txt',
+            'egglinker.txt', 'easy_install.txt', 
             setUp=linkerSetUp, tearDown=linkerTearDown,
             checker=renormalizing.RENormalizing([
                (re.compile('(\S+[/%(sep)s]| )'