Address review comments.

src/allmydata/scripts/common.py

@@ -1,6 +1,7 @@
 # coding: utf-8
 
 from __future__ import print_function
+from six import ensure_str
 
 import os, sys, textwrap
 import codecs
@@ -286,7 +287,5 @@ def escape_path(path):
     """
     segments = path.split("/")
     result = "/".join([urllib.parse.quote(unicode_to_url(s)) for s in segments])
-    # fixme: test.cli.test_create_alias fails if it gets Unicode on Python 2
-    if PY2 and isinstance(result, type(u'')):
-        result = result.encode('ascii')
+    result = ensure_str(result, "ascii")
     return result

src/allmydata/scripts/runner.py

@@ -174,8 +174,9 @@ def _maybe_enable_eliot_logging(options, reactor):
     return options
 
 def run():
-    if not six.PY2:
-        warnings.warn("Support for Python 3 is experimental. Use at your own risk.")
+    if six.PY3:
+        warnings.warn("Support for Python 3 is an incomplete work-in-progress."
+                      " Use at your own risk.")
 
     if sys.platform == "win32":
         from allmydata.windows.fixups import initialize

src/allmydata/test/test_runner.py

@@ -12,6 +12,9 @@ from __future__ import unicode_literals
 from future.utils import PY2
 if PY2:
     from future.builtins import filter, map, zip, ascii, chr, hex, input, next, oct, open, pow, round, super, bytes, dict, list, object, range, str, max, min  # noqa: F401
+
+from six import ensure_text
+
 import os.path, re, sys
 from os import linesep
 
@@ -19,8 +22,6 @@ from eliot import (
     log_call,
 )
 
-import six
-
 from twisted.trial import unittest
 
 from twisted.internet import reactor
@@ -83,9 +84,7 @@ def run_bintahoe(extra_argv, python_options=None):
     :return: A three-tuple of stdout (unicode), stderr (unicode), and the
         child process "returncode" (int).
     """
-    # fixme: below, 'unicode_to_argv' is called so ensure that
-    # executable is unicode to support that expectation.
-    executable = sys.executable.decode('utf-8') if six.PY2 else sys.executable
+    executable = ensure_text(sys.executable)
     argv = [executable]
     if python_options is not None:
         argv.extend(python_options)