Index: setuptools/command/easy_install.py
===================================================================
--- setuptools/command/easy_install.py	(revision 64985)
+++ setuptools/command/easy_install.py	(working copy)
@@ -1421,6 +1421,8 @@
         executable = "python.exe"
     else:
         executable = nt_quote_arg(executable)
+    if sys.platform.startswith('java'):
+        executable = fix_sh_shebang(executable)
     hdr = "#!%(executable)s%(options)s\n" % locals()
     if unicode(hdr,'ascii','ignore').encode('ascii') != hdr:
         # Non-ascii path to sys.executable, use -x to prevent warnings
@@ -1637,6 +1639,23 @@
     import setuptools; argv0 = os.path.dirname(setuptools.__path__[0])
     sys.argv[0] = argv0; sys.argv.append(argv0); main()
 
+def fix_sh_shebang(executable):
+    """Fix the shebang line for platforms (Jython) with a .sh
+    sys.executable.
+    
+    Shebang line interpreters can't be other shell scripts, so we prefix
+    these executables with /usr/bin/env in shebang lines.
+    """
+    try:
+        fp = open(executable)
+        magic = fp.read(2)
+        fp.close()
+    except (OSError,IOError):
+        return executable
+    if magic == '#!':
+        executable = '/usr/bin/env %s' % executable
+    return executable
+
 
 def main(argv=None, **kw):
     from setuptools import setup