[Distutils] Specifying version information once

[Jean-Paul Calderone]

Hello,

For a long time, the idiom I've used to specify version information in my
distutils-based packages has been this simple one: put version information
into the Python package somewhere, structure the source layout so that the
package can be imported directly from an unpacked source tarball (or vcs wc),
and import the version into setup.py.  This worked great.  And I only had to
define my version once.

Increasingly, it seems that new distutils-related tools don't support this
idiom and break in various ways.  (eg

  http://divmod.org/trac/ticket/2629
  http://divmod.org/trac/ticket/2831
)

What is the recommendation for specifying version information in a way which
is compatible with all these new tools?

Jean-Paul