[Distutils] Side by side debug/non-debug eggs

[Stephen Waterbury]

Jean-Paul Calderone wrote:
> On Fri, 22 May 2009 11:33:54 -0400, "P.J. Eby" <pje at telecommunity.com> 
> wrote:
>> At 09:45 AM 5/22/2009 -0400, Jean-Paul Calderone wrote:
>>> Hello all,
>>>
>>> Prior to eggs, if I wanted to have debug and non-debug versions of an
>>> extension module available, I could build and install the extension
>>> twice and the modules would happily co-exist, for example:
>>>
>>>
>>>  $ python setup.py build install
>>>  ...
>>>  $ python-dbg setup.py build install
>>>  ...
>>>  $ .../site-packages/twisted/python$ ls *.so
>>>  _epoll_d.so  _epoll.so
>>>  $ .../site-packages/twisted/python$
>>> If I then ran a debug build of Python, the debug extension would be 
>>> loaded.
>>> When I ran a normal build of Python, the non-debug extension would be 
>>> loaded.
>>> However, with eggs, each new egg completely replaces the last egg.  
>>> There
>>> seems to be no possibility for side-by-side builds.  Am I overlooking a
>>> feature of eggs or of setuptools?
>>
>> Have you tried "setup.py develop"?  This builds extensions in-place in 
>> the source tree and adds the source tree to sys.path.
>>
> 
> Aware of it, but I haven't tried it.  In this use, it sounds very
> similar to "setup.py build_ext -i", which also partially solves the
> problem.  Unfortunately, some packages have their source laid out
> such that they cannot actually be used in-place, only after they've
> been installed.

A data point:  I've been using "setup.py develop" with twisted
for over a year now, and it works great for me -- definitely one of
my favorite features of setuptools.  I use it with an svn checkout of
twisted so I can always use the latest -- especially nice with twisted
because of its high quality management (trunk is almost never broken).
That way I can easily track the latest version -- just do an svn
update, no further installation required.

When I want to try a vcs checkout of an immature package and its setup.py
uses distutils instead of setuptools, I'll try changing its setup.py to
use setuptools (usually a one or two line replacement of the import)
and see if "setup.py develop" works, and it almost always does.

Steve