* document "Import From Derivation"
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Co-authored-by: John Ericson <git@JohnEricson.me>
make the example more realistic, since `headers` is not an output name
used in Nixpkgs
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
derivations are about data transformation, so the term "build" does not
add any information. there was also some feedback that "build task" is
not more helpful than "derivation" if you have no prior experience with
Nix or build systems, while existing associations may be misleading.
Was confused why `make html` didn't work while working on #9032, but
then I realized that after this section was written, the target was
renamed to `manual-html` in 6910f5dcb6.
Before they were an "ad-hoc" header with bold and a colon; now they are
a proper subheader.
For the man pages, this doesn't make much of a difference, but it will
help more on for the HTML manual, where things can be restyled. Again,
good separation of content vs presentation.
Behavior change:
Before we only showed uption if the command-specific options were
non-empty. But that is somewhat odd since we also show common options.
Now, we do everything based on the union of both sorts of options (with
hidden-categories filtered, as before).
Implementation change:
The JSON dumping once again includes all options; the filtering of
hidden categories is done in the Nix instead. This is better separation
of "content" vs "presentation", and prepare the way for the HTML manual
vs manpages / `--help` doing different things.
there is a very confusing warning in the Nixpkgs manual that
mischaracterises `nix-env` behavior, and this example shows what's
really happening.
note that it doesn't use `pkgs.runCommand` or other `pkgs.stdenv`
facilities, as deep down those set `meta.outputsToInstall` to very
particular defaults that do not generally apply to Nix.
We use the same nested map representation we used for goals, again in
order to save space. We might someday want to combine with `inputDrvs`,
by doing `V = bool` instead of `V = std::set<OutputName>`, but we are
not doing that yet for sake of a smaller diff.
The ATerm format for Derivations also needs to be extended, in addition
to the in-memory format. To accomodate this, we added a new basic
versioning scheme, so old versions of Nix will get nice errors. (And
going forward, if the ATerm format changes again the errors will be even
better.)
`parsedStrings`, an internal function used as part of parsing
derivations in A-Term format, used to consume the final `]` but expect
the initial `[` to already be consumed. This made for what looked like
unbalanced brackets at callsites, which was confusing. Now it consumes
both which is hopefully less confusing.
As part of testing, we also created a unit test for the A-Term format for
regular non-experimental derivations too.
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
Apply suggestions from code review
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
this removes a lot of noise from the web search, which precludes finding
the actual documentation.
some configuration settings have enough documentation to warrant
individual pages, so the alternative of including full setting
documentation in each command page doesn't make much sense here.
this change technically means that the command line flags to override
settings are "invisible", and not exported as JSON. this may or may not
be desirable. a more explicit approach would be adding a `hidden` field
to the flag's JSON output, but would also require adjusting
post-processing of that JSON for manual rendering.
