- Quote the 'spec' argument, as in the case of installing an egg from
  the buildout-cache, if the filename contains spaces it would fail

CHANGES.txt

@@ -7,6 +7,9 @@ Change History
 1.0.4 (unreleased)
 ==================
 
+- Quote the 'spec' argument, as in the case of installing an egg from
+  the buildout-cache, if the filename contains spaces it would fail (sidnei)
+
 - Extended configuration syntax to allow -= and += operators (malthe).
   
 1.0.3 (2008-06-01)

src/zc/buildout/easy_install.py

@@ -272,7 +272,7 @@ class Installer:
             elif level < 0:
                 args += ('-v', )
 
-            args += (spec, )
+            args += (_safe_arg(spec), )
 
             if level <= logging.DEBUG:
                 logger.debug('Running easy_install:\n%s "%s"\npath=%s\n',