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.
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.
This commit changes the default path of the Home Manager configuration
file from `~/.nixpkgs/home.nix` to `~/.config/nixpkgs/home.nix`. The
old path is still supported and will be used if the `.config` path
does not exist.
This aligns Home Manager with the preferred configuration directory in
NixOS 17.03.
Fixes#13.
This removes the old argument based method that Home Manager used to
find its modules by a `NIX_PATH` based method. Specifically, this adds
a `home-manager` Nix path prefix that can be overridden much like with
the `nixpkgs` path prefix.
For example, with these settings Bash will complain if uninitialized
variables are used. Some code has been improved to run cleanly with
these settings.
Nix needs an absolute path and the user may have given a relative path
for the configuration file. We therefore need to expand it using the
`realpath` tool.
