This is already used by Hydra, and is very useful when materializing
a remote builder list from service discovery. This allows the service
discovery tool to only sync one file instead of two.
This is technically a breaking change, since attempting to set plugin
files after the first non-flag argument will now throw an error. This
is acceptable given the relative lack of stability in a plugin
interface and the need to tie the knot somewhere once plugins can
actually define new subcommands.
http://nixos.org redirects to https://nixos.org and apparently the HTTP library doesn't follow the redirect, so the output is empty.
When defining https in the request it crashes because the library doesn't seem to support https.
So this switches the example to a different http library.
As we are working towards Nix 3.0 we want to make sure that we make a
huge step forward in Nix's user experience. And once 3.0 is out of the
door we need to make sure that all future commands and features keep up
the standard of user experience.
This PR adds a CLI guideline document to the Nix documentation. Consider
this document a good starting point and a checklist when somebody will
be (re)implementing commands.
Clearly this guideline does nothing to improve user experience on its
own and can only be useful as long as it is going to be read and
cared for. But it is a first step into that direction.
Since c4c3c15c19 (#4251) building Nix for
macOS with sandboxing fails:
```
getting status of /nix/var/nix/profiles/per-user/root/channels/nixpkgs: Operation not permitted
```
This happens, because `EvalSettings::getDefaultNixPath` tries to access
paths outside the sandbox. Since the state-dir is not required for
doc generation, it is set to the dummy folder. This needs to be done
for all nix invocations during doc generation, as
`EvalSettings::getDefaultNixPath` is called unconditionally.
This removes the extra-substituters and extra-sandbox-paths settings
and instead makes every array setting extensible by setting
"extra-<name> = <value>" in the configuration file or passing
"--<name> <value>" on the command line.
