str(NoSuchChildError(nonascii)) raises an exception, causing the actual name to be lost in tracebacks

[davidsarah]

C:\tahoe\furry>bin\tahoe debug repl
Python 2.7.1 (r271:86832, Nov 27 2010, 18:30:46) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
(InteractiveConsole)
>>> from allmydata.interfaces import NoSuchChildError
>>> str(NoSuchChildError(u'\u2621'))
Traceback (most recent call last):
  File "<console>", line 1, in <module>
UnicodeEncodeError: 'ascii' codec can't encode character u'\u2621' in position 0: ordinal not in range(128)

Despite this, Twisted trial usually manages to print tracebacks in unit test errors successfully. However it still causes ugliness and loss of information, for example:

[ERROR]
Traceback (most recent call last):
  File "c:\tahoe\furry\src\allmydata\dirnode.py", line 444, in _get
    raise NoSuchChildError(name)
allmydata.interfaces.NoSuchChildError: <NoSuchChildError instance at 0x226b558 with str error:
 Traceback (most recent call last):
  File "C:\Python27\lib\site-packages\twisted-10.2.0-py2.7-win32.egg\twisted\python\reflect.py", line 546, in _safeFormat
    return formatter(o)
UnicodeEncodeError: 'ascii' codec can't encode character u'\xf8' in position 1: ordinal not in range
(128)
>

[davidsarah]

interfaces.py: ensure that NoSuchChildError? can be converted to str even when it is for a non-ASCII name. fixes #1483

[thedirtycalvinist]

Seems simple enough to me and matches the suggested definition of that function in the Python documentation: ​http://docs.python.org/tutorial/errors.html#tut-userexceptions

[davidsarah]

Will apply immediately after 1.9.

[david-sarah@…]

In 93e50f5e1616004a:

interfaces.py: ensure that NoSuchChildError? can be converted to str even when it is for a non-ASCII name. fixes #1483

[david-sarah <david-sarah@…>]

In 93e50f5e1616004a:

interfaces.py: ensure that NoSuchChildError? can be converted to str even when it is for a non-ASCII name. fixes #1483