First argument to ctypes.CDLL can be None

[virtuald]

If you try to wrap pip with pyinstaller on Ubuntu 14.04, it fails because it calls ctypes.CDLL(None) (see https://github.com/pypa/pip/blob/8.1.2/pip/pep425tags.py#L188).

This fixes that and adds a test.

[virtuald]

Disclaimer: I haven't tested this on Windows, nor have I actually ran the tests... but I assume that Travis will do that for me. :-D

[htgoebel]

Hmm, would name='' be an valid input? I assume if name: would be a better test here.

(When changing this, please remove the trailing whitespace in line 125, too. Thanks.)

[htgoebel]

Thanks for this fix. I'll merge it when you worked on the one line-commend I had.

[virtuald]

Comments addressed.

[htgoebel]

Thanks for the quick update (and for the hook of course).

[bjones1]

Help! This breaks on Windows -- see https://ci.appveyor.com/project/matysek/pyinstaller/build/1232/job/ddjsih612lr1fl84#L1386, for example. Would you fix this?

[virtuald]

I'm currently on vacation, no access to an actual computer until August 7.
On Jul 22, 2016 22:58, "Bryan A. Jones" notifications@github.com wrote:Help! This breaks on Windows -- see https://ci.appveyor.com/project/matysek/pyinstaller/build/1232/job/ddjsih612lr1fl84#L1386, for example. Would you fix this?

—You are receiving this because you authored the thread.Reply to this email directly, view it on GitHub, or mute the thread.

[htgoebel]

This Appveyor really gets me on my nerves. It always breaks for reasons beyond our scope, so yoe never know if ones code will really introduce a bug or it just appveror again.

@bjones1 I'll disable this check for windows for now.

[bjones1]

@htgoebel, I agree -- Appveyor has been very frustrating in the past. I'm hoping that recent changes will help make it more useful; in the recent past, it's:

• Started failing because of a hosting change (Appveyor-induced problem).
• Flagged a fix needed for cherrypy (good).
• Just detected a Windows-only problem with ctypes (good).
• Revealed a problem in Python 2.7 multiprocessing (good).

The biggest problem right now IMHO is speed -- it takes too long to get feedback, particularly yesterday where for some reason it was backed up almost 24 hours. Currently, it's build queue is almost empty, so hopefully that will be getter.

It's working...frustrating at times, but working...

[bjones1]

@virtuald, would you work on fixing this? It's still a problem for Windows.

[bjones1]

@htgoebel, is there any reason not to merge the fix-2098-on-windows branch? I'd like to get Appveyor working again, and this is a blocker.

[htgoebel]

@bjones1 pardon, which fix-2098-on-windows branch?

[virtuald]

Oh, sorry, fell off my radar. I can do something about this tonight if someone doesn't beat me to it.

[bjones1]

@virtuald, great, thanks!

@htgoebel, this one: https://github.com/pyinstaller/pyinstaller/tree/fix-2098-on-windows.

[htgoebel]

@bjones1 I don’t know why this branch is not merged. You worked on it, as far as I can see. Is there any reason for not merging it?

[bjones1]

Great! I'll merge.

[virtuald]

@bjones1 What exactly is the problem on Windows? It appears that 1ec2473 disabled the test on Windows. Or is there another issue?

I get this on linux (Python 2.7.12):

>>> import ctypes
>>> ctypes.CDLL(None)
<CDLL 'None', handle 7fdbd4645128 at 7fdbd44d2910>

I get this on Windows (Python 2.7.12 under wine, but I assume it's the same):

>>> import ctypes
>>> lib = ctypes.CDLL(None)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "....\ctypes\__init__.py", line 362, in __init__
    self._handle = _dlopen(self._name, mode)
TypeError: expected string or Unicode object, NoneType found

Should we duplicate the behavior on Windows?

[bjones1]

I see something very similar:

Python 3.5.1 |Anaconda 4.0.0 (32-bit)| (default, Mar  4 2016, 15:28:01) [MSC v.1900 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import ctypes
>>> lib = ctypes.CDLL(None)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\bjones\Downloads\Anaconda3\lib\ctypes\__init__.py", line 347, in __init__
    self._handle = _dlopen(self._name, mode)
TypeError: bad argument type for built-in operation
>>>

So, it looks like the behavior of ctypes.CDLL(None) differs on Windows and Linux. I didn't realize this before -- so, the fix already made by @htgoebel is sufficient (skip the test case on Windows). There's no additional work needed; thanks, @virtuald, for helping me see this!