It is referenced in various places, but does not work out of the box:
$ nixos-help
/run/current-system/sw/bin/nixos-help: unable to start a web browser; please set $BROWSER
In the user-hidden fallbacks to xdg-open(1) and w3m(1), `nixos-help`
expects tools to be deliberately installed by users.
For default installations and new users in general, this is unlikely to
be the case. Conversely, chances to use `nixos-help` are even higher
in such cases.
Use w3m-nographics by default to ensure documentation is always
available. The documentation browser on ttyS8 already does so, but is
not accessible in every installation, e.g. VMs with only ttyS0 and SSH
available.
This obsoletes including it in the base profile's systemPackages,
so remove the @TODO as done.
Before this change `man 5 configuration.nix` would only show options of modules in
the `baseModules` set, which consists only of the list of modules in
`nixos/modules/module-list.nix`
With this change applied and `documentation.nixos.includeAllModules` option enabled
all modules included in `configuration.nix` file will be used instead.
This makes configurations with custom modules self-documenting. It also means
that importing non-`baseModules` modules like `gce.nix` or `azure.nix`
will make their documentation available in `man 5 configuration.nix`.
`documentation.nixos.includeAllModules` is currently set to `false` by
default as enabling it usually uncovers bugs and prevents evaluation.
It should be set to `true` in a release or two.
This was originally implemented in #47177, edited for more configurability,
documented and rebased onto master by @oxij.
This installs the kio "man:" protocol handler, which fixes the UNIX manual
section in the KDE Help Center.
Note that kde currently parses "/etc/man.conf" manually, if `$MANPATH` is not
set, to build its man page index. (if https://bugs.kde.org/show_bug.cgi?id=404022
is addressed, the "/etc/man.conf" symlink should not be necessary anymore)
lib.optional returns a singleton or an empty list. Therefore the
argument does not need to be wrapped in a list.
An alternative patch could have used lib.optionals but seems like no
more elements are going to be added to the optional list.
I know that "devinfo" output does not currently exist, but so does "devman".
It is mentioned in the nixpkgs manual, but no derivation in nixpkgs actually uses it.
