Tests.

rubygems.py

@@ -92,7 +92,7 @@ class Recipe(object):
         }
         env_override = self.options.get('environment', '')
         env_override = self._get_env_override(env_override)
-        env = {k: v % env for k, v in env_override}
+        env.update({k: v % env for k, v in env_override})
         return env
 
     def _get_latest_rubygems(self):

tests/buildout.cfg

+[buildout]
+parts =
+    rubygems
+
+develop =
+    ..
+
+[rubygems]
+recipe = rubygemsrecipe
+gems =
+    sass
+    compass==0.10

tests/runtests.py

+#!/usr/bin/env python
+
+import re
+import os.path
+import logging
+import subprocess
+
+
+def sh(cmd):
+    retcode = subprocess.call(cmd, shell=True)
+    assert retcode == 0
+
+def shr(cmd):
+    return subprocess.check_output(cmd, shell=True)
+
+
+def clean():
+    logging.info('Cleaning environment...')
+    paths = (
+        '.installed.cfg',
+        'bin',
+        'bootstrap.py',
+        'develop-eggs',
+        'include',
+        'lib',
+        'local',
+        'parts',
+    )
+    for path in paths:
+        if os.path.exists(path):
+            sh('rm -r %s' % path)
+
+
+def main():
+    logging.basicConfig(
+        format='%(message)s',
+        level=logging.INFO
+    )
+    clean()
+    sh('wget http://downloads.buildout.org/2/bootstrap.py')
+    sh('virtualenv --no-site-packages .')
+    sh('bin/pip install --upgrade setuptools')
+    sh('bin/python bootstrap.py')
+    sh('bin/buildout')
+    assert re.match(
+        r'^Sass \d+(\.\d+){2} \([a-zA-Z ]+\)$',
+        shr('bin/sass --version').strip()
+    )
+
+
+
+if __name__ == '__main__':
+    main()