[tahoe-dev] Build problems: using installed packages, and install failure

[Jack Lloyd]

A number of Tahoe's dependencies (including Twisted, Crypto++, etc)
are already installed on my system. But if I run
`python setup.py build`

I see things like:

Searching for Twisted>=2.4.0
Best match: Twisted 8.2.0
Downloading http://allmydata.org/source/tahoe/deps/tahoe-dep-sdists/Twisted-8.2.0.tar.bz2

How do I tell Tahoe to use already installed versions where possible?
This is going to be essential for getting an tahoe-lafs ebuild into
Gentoo, I think.

Continuing on, I get this:

"""
Installed /home/lloyd/projects/tahoe/Twisted-8.2.0-py2.6-linux-x86_64.egg
running darcsver
running develop
Checking .pth file support in support/lib/python2.6/site-packages
error: can't create or remove files in install directory

The following error occurred while trying to add or remove files in the
installation directory:

    [Errno 2] No such file or directory: 'support/lib/python2.6/site-packages/test-easy-install-19886.pth'

The installation directory you specified (via --install-dir, --prefix, or
the distutils default setting) was:

    support/lib/python2.6/site-packages
"""

I'm sure this is pilot error of some kind, but I don't see what I'm
doing wrong.

This is darcs head.

-Jack