Use __import__() to avoid leaking imported names to the executed script.

setuptools/script (dev).tmpl

 # EASY-INSTALL-DEV-SCRIPT: %(spec)r,%(script_name)r
 __requires__ = %(spec)r
-import sys
-from pkg_resources import require
-require(%(spec)r)
-del require
+__import__('pkg_resources').require(%(spec)r)
 __file__ = %(dev_path)r
-if sys.version_info < (3, 0):
+if __import__('sys').version_info < (3, 0):
     execfile(__file__)
 else:
     exec(compile(open(__file__).read(), __file__, 'exec'))

setuptools/script.tmpl

 # EASY-INSTALL-SCRIPT: %(spec)r,%(script_name)r
 __requires__ = %(spec)r
-import pkg_resources
-pkg_resources.run_script(%(spec)r, %(script_name)r)
+__import__('pkg_resources').run_script(%(spec)r, %(script_name)r)