By not using the home file name in a derivation name, the home file name
is no longer exposed to the naming restrictions for nix store paths.
For example, it's now possible to define home files with spaces in their
names without providing a target or source attribute.
This command allows the user to examine the news items generated by
the news module. See #52.
Many thanks to @nonsequitur and @uvNikita for suggestions and
improvements.
Using `--no-out-link` is convenient but it does not set up a GC root,
so an unfortunately timed GC could remove the generation before
activation completes. Many thanks to @nonsequitur for noting this
problem.
1. It slows down the initial start: it takes around 2s at first launch,
and around 0.25s for the following launches;
2. It seems to be redundant since just installing zsh package gives
working completions with correct $fpath set.
There is no need to specify an out link when switching to a new
generation since nix-build prints the store path on standard output.
Similarly, when just building a generation we specify no out link
since nix-build will use "result" by default.
Technically not necessary but it was a bit silly to leave out this
important directory from the generation directory. This also makes it
more convenient to browse the installed packages after a
`home-manager build`.
With --ignore-fail-on-non-empty, non-emptiness is the only failure
that gets ignored by rmdir. In the case that rmdir reaches $HOME and
considers deleting it, it will detect insufficient permissions and
subsequently exit with an error, even if $HOME is not empty.
Prevent this by calling rmdir with a relative path that excludes
$HOME.
Run the activation script in its original nix-store location so that
Bash error messages show the real script location instead of 'wrkdir',
which gets deleted right after the script exits.
Because 'set -e' has no effect on commands that run in an if condition,
the script was always exiting with no error when 'doBuild' failed.
As a bonus, $wrkdir is now always removed after building.
We must only follow the symbolic link once (i.e., not use the `-e`
option) since otherwise the pattern will not match when
`home.file.xyz.source` is a directory.
If the `home-manager` module is enabled then check if the
`home-manager` package is installed using `nix-env -i` and if so then
it is automatically uninstalled before the new package environment,
which includes home-manager, is installed.
