A patch that replaced the original file with a symlink to nix store was
reverted because MacOS Network framework doesn't support symlinks for
the file.
The revert leaves the system without any /etc/hosts file at all though.
To fix this, an activation step is added to restore the original file
from .before-nix-darwin backup, if it exists.
Signed-off-by: Ihar Hrachyshka <ihar.hrachyshka@gmail.com>
When `nix.enable` is off, we don’t necessarily have an active
Nix installation, so there won’t necessarily be an active
`/nix/var/nix/gcroots` directory to link things into. NixOS just skips
this unconditionally when `nix.enable` is off, but that doesn’t
work well with a context in which we usually expect `nix.enable`
to be coupled with an unmanaged system installation of Nix.
When we’re not managing the Nix installation, these defaults
aren’t used out of the box and won’t accurately represent the
state of any unmanaged Nix or the desired Nix package, so reading
the option defaults is a bug.
This was previously a warning for `nix.package` and a silent failure
for all the others. Now that all the problematic accesses in nix-darwin
have been appropriately conditionalized, and since a throw gives a
backtrace where a warning doesn’t, give throwing defaults to all the
`nix.*` options that don’t reflect reality and that that modules
shouldn’t be reading when `nix.enable` is off.
I’m not in love with the implementation strategy here… ideally
we’d think of something better than this and then upstream it to
NixOS. `nix.nrBuildUsers` growing a fake default that is never used
is particularly unfortunate. But this should hopefully catch mistakes
in module code reasonably reliably.
Currently, setting `homebrew.masApps` causes `"mas"` to automatically
be added to `homebrew.brews`. Users who want to use Homebrew only
for managing App Store apps and casks, like me, can override this
by setting `homebrew.brews = lib.mkForce [ ];` and adding Nixpkgs’
`mas` to their `environment.systemPackages`.
When the activation script path no longer depends on the built
configuration’s `environment.systemPackages`, this will no longer
work. Since this was originally added before `mas` was packaged in
Nixpkgs and we now have a perfectly serviceable binary package,
we can add it to the `$PATH` when invoking Homebrew and skip the
automatic formula installation.
As the Homebrew `bin` directory still comes first, users who
specifically want the formula can restore the previous behaviour by
explicitly adding `"mas"` to `homebrew.brews`.
Closes: #1314
Currently, the `bin` directory of the configured system
is embedded in the `$PATH` of activation scripts, but not
other elements of the default `environment.systemPath` like
`/nix/var/nix/profiles/default/bin` or `/usr/local/bin`. This
means that when nix-darwin is not managing the Nix installation,
activation scripts like Home Manager’s that want to look up the
system‐managed Nix can’t find it. Search for it on the entire
`environment.systemPath` and add the appropriate directory if found.
We leave the launchd `activate-system` daemon alone, because it has
erroneously referred to `@out@/sw/bin` forever and therefore never got
a Nix on the path to begin with. That’s a problem for another time.
(The more ideal solution is probably for Home Manager activation to
be driven by launchd or something, but that’s a longer‐term goal.)
