Having N different copies of the NixOS kernel configuration is bad
because these copies tend to diverge. For instance, our 3.10 config
lacked some modules that were enabled in older configs, probably
because the 3.10 config had been copied off an earlier version of some
older kernel config.
So now there is a single kernel config in common-config.nix. It has a
few conditionals to deal with new/removed kernel options, but
otherwise it's pretty straightforward.
Also, a lot of cut&paste boilerplate between the kernel Nix
expressions is gone (such as preConfigure).
Change PATH=$PATH:deps to PATH=deps:$PATH in the wicd wrappers, because
the latter is more deterministic; it prevents possibly wrong versions of
dependencies to sneak in from the environment.
Do the same for PYTHONPATH.
It doesn't make sense to build tools/applications with three different
python interpreter versions, so move them out of python modules list.
Also reverts 53ffc6e0ef.
We cannot import the packages from all of these three packages sets into
the global namespace, because they are indistinguishable. For example:
$ nix-env -qaP \* | grep pylint
pypyPackages.pylint pylint-0.26.0
python33Packages.pylint pylint-0.26.0
python27Packages.pylint pylint-0.26.0
When someone tries to install pylint by running "nix-env -i pylint",
then it's impossible to tell which one of these three versions was
chosen.
I can think of two ways to remedy this problem with recurseIntoAttrs:
1) Bake the name of the Python interpreter into every package's name,
i.e. offer "python27-pylint", "python33-pylint", and so on.
2) Ensure that all non-default package sets mark all their packages
'lowPrio' to unsure that the choice during installation is
deterministic.
OfflineIMAP is primarily a program/tool, not a python module (although
it installs a python module too, for those who want to poke at its
internals).
Now we can install it with "nix-env -i offlineimap" instead of
"nix-env -i python2.7-offlineimap".
