The main two changes are
1. Completely rewrite how with-packages works to remove use of envHooks
2. The package description is now an idris specific set rather than
being a subset of the arguments to mkDerivation. This mirrors the
way Haskell packages are treated.
Of course, you'll get a bunch of warnings from the activation script:
$ nixos-enter --root /tmp/mnt/
setting up /etc...
mount: /dev: permission denied.
mount: /dev/pts: permission denied.
mount: /dev/shm: permission denied.
mount: /sys: permission denied.
/nix/var/nix/profiles/system/activate: line 74: /proc/sys/kernel/modprobe: Permission denied
chown: changing ownership of '/run/wrappers/wrappers.0pKlU8JsvV/dbus-daemon-launch-helper': Invalid argument
NOTE: Under Linux, effective file capabilities must either be empty, or
exactly match the union of selected permitted and inheritable bits.
Failed to set capabilities on file `/run/wrappers/wrappers.0pKlU8JsvV/ping' (Operation not permitted)
chown: changing ownership of '/run/wrappers/wrappers.0pKlU8JsvV/unix_chkpwd': Invalid argument
[root@nixos:/]#
Sometimes it's needed to override parts of `vim_configurable`, for
instance when using ENSIME (http://ensime.github.io/), in this case you
need a Python interpreter and the modules `sexpdata` and
`websocket_client`.
However overriding `vim_configurable` is quite hard as we run
`vimUtils.makeCustomizable` over the default comming from
`configurable.nix`. Therefore it's necessary to copy the code from
`all-packages.nix` and alter the parts you need: https://nixos.org/nix-dev/2017-April/023364.html
In order to simplify overriding `vim_configurable` I added an
`override` and an `overrideAttrs` function to `vimutils.makeCustomizable`
to ensure that the customization capabilities won't be lost after
altering the derivation.
Now it's possible to write expressions like this without evaluation
failures:
```
with pkgs;
let
vimPy3 = vim_configurable.override {
python = python3;
};
in vimPy3.customize { ... }
```
Michael Alan Dorman