Re: Psycopg2 Windows packaging

Hi Aleksi,

As Daniele noted, the latest release (2.6.2) does have windows whl files on
the PyPI page. This is something new added in the past two releases. When
we looked into distributing the whl files on PyPI, I considered including
the .exes, but opted against it since wheels were looking to be the
preferred method of distributing and the main reason for including them in
PyPI was for PIP to be able to install them, ie the following works on
windows with PIP and Python versions 2.6, 2.7, 3.2-3.5:

pip install psycopg2

As for building the binaries, distutils use the same compiler version that
the python binaries were built with. This means you need the following
compilers for the following Python Versions:

Visual Studio 2015 (Visual C++ 14.0)

Python 3.5

Visual Studio 2010 (Visual C++ 10.0)

Python 3.4
Python 3.3

Visual Studio 2008 (Visual C++ 9.0)

Python 3.2
Python 3.1
Python 3.0
Python 2.7
Python 2.6

Several years back, I had a problem that when multiple versions of VS were
installed on a machine, at least one version of was sucking in libraries
from another. My solution was to create a virtual machine for each version
of Visual Studio to isolate them (Note, this isn't the same DLL hell that
Daniele referred to).

I am not familiar with AppVeyer, so I don't know its strengths or
limitations. One requirement of a build environment is that it needs to
support different versions of Visual C++ for compiling as noted above. The
other requirement is that there are dependency libraries that need to be
built with the same compiler version and available for linking. Psycopg2
is linked against the following libraries:

zlib
openssl
postgresql (libpq)

If we can make AppVeyer work, I would be glad to move to it.

Anything you can contribute would be appreciated. Feel free to shoot me
any questions.

-jason

On Tue, Nov 8, 2016 at 6:44 AM, Aleksi Häkli <aleksi(dot)hakli(at)vincit(dot)com>
wrote:

> Hi, and thanks for the in-depth answer! I did not realize the package was
> compiled and functional under Win :)
>
> In which way is it easiest to contact Jason and is there an IRC channel or
> something alike besides this mailing list for this discussion?
>
> I'd be interested in helping out with the Windows distribution track if
> there is need and space for new contributors on that front, but would like
> to discuss with the current Windows packager and I do not have his contact
> information.
>
> I have decent experience in Python packaging on Linux and think that the
> Windows DLL hell is a thing that could be documented and sorted out in
> itself. In addition to that, I saw that AppVeyor seems to support OSS
> projects and Windows builds for free:
>
> https://www.appveyor.com/pricing/
>
> I am not aware of the current build configuration so forgive me if I'm
> jumping ahead myself in this.
>
> BR,
> Aleksi
>
> On 8 November 2016 at 15:34, Daniele Varrazzo <daniele(dot)varrazzo(at)gmail(dot)com>
> wrote:
>
>> On Tue, Nov 8, 2016 at 12:45 PM, Aleksi Häkli <aleksi(dot)hakli(at)vincit(dot)com>
>> wrote:
>> > Hello,
>> >
>> > I was wondering about the psycopg2 Windows package. Is there any
>> particular
>> > reason the package is not distributed for Windows as a precompiled
>> binary
>> > through pip? I always install the precompiled executables by
>> Stickpeople or
>> > the precompiled wheels by Gohlke, and have never had the actual need to
>> > install the package on any Windows platform from source (since it is so
>> > tedious).
>>
>> It is, relatively recently.
>>
>> https://pypi.python.org/pypi/psycopg2
>>
>> The why is: the original author (Federico) is not a Windows user. I
>> was when I joined the project: I actually started contributing to
>> psycopg2 with patches to compile with mingw, but Jason (correct me if
>> I'm wrong) compiles libpq, psycopg, and other required libraries using
>> the same MS compiler for the target Python version, guaranteeing I
>> think to avoid to open the door of DLhell. My expertise in that field
>> stops at Windows 2000.
>>
>> > Would it not be easier for everybody to distribute the package via PyPI
>> as a
>> > pip installable pre compiled signed binary instead of the current source
>> > format which mostly makes the package uninstallable on the platform?
>> >
>> > I have ran into the installation issue about 5 years in row, developing
>> with
>> > both Windows and Linux, and write my own scripts to avert the issue,
>> but I
>> > think it causes unnecessary headaches for many junior developers. All
>> senior
>> > developers can probably compile the library themselves if need be.
>>
>> I haven't used Windows in the last 10 years, and I don't feel the urge
>> to start doing it again. This is a free software project, made by
>> volunteers with limited spare time in their hands and absolutely zero
>> funding. Nobody has ever stepped ahead more than Jason has to support
>> a platform he cares about, and while I make an effort to avoid
>> breaking Windows build, if he wasn't around I wouldn't personally
>> care. You are very welcome to do some work yourself to support the
>> library the way you want, or to finance the development of the feature
>> you care about. If you don't, you get what you pay for, which is what
>> who pays with time or money needs.
>>
>> -- Daniele
>>
>
>
>
> --
> Aleksi Häkli
> +358 400 357 013
> aleksi(dot)hakli(at)vincit(dot)com
>