* doc: add stdenv passthru chapter
Broad strokes:
- create the chapter
- move existing stdenv passthru coverage into it
- move out-of-place coverage of passthru.tests from the stdenv meta chapter into it
- (try to) apply 1-sentence-per-line to text I've touched
- add legacy anchors for everything moved
- update existing links to the new anchors
- add tentative motivating text
- make nixpkgs-internal links relative/branchless
razor: if it is only ever needed by contributors, which is likely if links
refer to the latest revision of the source code, then it's for
the contributor guide
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
Following [Best Practices](https://nix.dev/guides/best-practices#with-scopes),
`with` is a problematic language construction and should be avoided.
Usually it is employed like a "factorization": `[ X.A X.B X.C X.D ]` is written
`with X; [ A B C D ]`.
However, as shown in the link above, the syntatical rules of `with` are not so
intuitive, and this "distributive rule" is very selective, in the sense that
`with X; [ A B C D ]` is not equivalent to `[ X.A X.B X.C X.D ]`.
However, this factorization is still useful to "squeeze" some code, especially
in lists like `meta.maintainers`.
On the other hand, it becomes less justifiable in bigger scopes. This is
especially true in cases like `with lib;` in the top of expression and in sets
like `meta = with lib; { . . . }`.
That being said, this patch removes most of example code in the current
documentation.
The exceptions are, for now
- doc/functions/generators.section.md
- doc/languages-frameworks/coq.section.md
because, well, they are way more complicated, and I couldn't parse them
mentally - yet another reason why `with` should be avoided!
https://www.pcre.org/
The `pcre` library is "now at end of life, and is no longer being
maintained," according to the upstream maintainers. Accordingly, we
should replace uses of `pcre` with its actively maintained successor,
`pcre2`, wherever possible .
Update instructions for manual build phases execution via `nix-shell` to
cover all phases. There is no easy way of getting those commands, so it
makes a sense to have them all properly documented.
While the word 'simply' is usually added to encourage readers, it often has the
opposite effect and may even appear condescending, especially when the reader
runs into trouble trying to apply the suggestions from the documentation. It is
almost always an improvement to simply drop the word from the sentence.
(there are more possible improvements like this, we can apply those in separate
PRs)
* doc/stdenv: rewrite manual build procedure to be closer to an auto-build
This is based on
<https://jade.fyi/blog/building-nix-derivations-manually/> plus some
more original research.
The previous version of this section did not work for your choice of
simple Haskell package, e.g. haskellPackages.hscolour, due to things
like `compileBuildDriverPhase` and other custom phases that it
does not address at all.
It seems more correct to use genericBuild in development to harmonize it
with what is actually done.
I feel a little bit like I am committing a sin by suggesting using the
experimental CLI in the manual (afaict I am the first to do this), but I
have given the old version of the command, and there are justifiable
reasons to do it:
* The noted limitations with env-vars are fixed. The one with the
non-empty temp directory was one I ran into myself and oh boy was that
not fun to debug.
* Additionally the outputs are set *before* sourcing `setup.sh`: there
is an issue with nix-shell where the original version of `$out` winds
up in `NIX_LDFLAGS` due to _addRpathPrefix, which means that resulting
executables may not run properly.
It is sad that `nix develop` propagates a wrong value of `SHELL` to
builders, though. It is equally sad that `nix-shell` is essentially
abandoned upstream, with undocumented and not insignificant differences
from `nix develop`.
For the exact script differences:
17e6b85d05/src/nix-build/nix-build.cc (L516-L551)db026103b1/src/nix/get-env.sh
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
* nixpkgs manual: add an alternative example in stdenv-separateDebugInfo
This change gets rid of the indirect reference to `nix-env -i` usage
and shows how to achieve the same goal with a shell expression.
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
The text was originally added [0] following an apparently incomplete
research on how everything plays together. In fact, Nix propagates
`outputs` to the corresponding nested derivations, and there is some
messy behavior in Nixpkgs that only seems to propagate
`meta.outputsToInstall` in `buildEnv`[1].
This change moves the hints on how to use NixOS specifics to NixOS
module documentation (which is hopefully easier to find through
search.nixos.org), describes the default behavior in Nixpkgs (updating
a the link to the source), and removes the confusing mention of
`nix-env`.
the last of them should not be there to begin with. we don't want
beginners to use `nix-env`, as this is known to run them into trouble
eventually.
[0]: https://github.com/NixOS/nixpkgs/pull/76794
[1]: 1774d07242/pkgs/build-support/buildenv/default.nix (L66)
* Updates meta.chapter.md with a reference link to the usage of the package description field instead of referring to nix-env
---------
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
also updates nixdoc to 2.3.0. the nixdoc update is not a separate commit
because that would leave the manual build broken for one commit,
potentially breaking bisects and rebases.
pandoc recognizes `::: note` admonitions, nixos-render-docs only
recognizes `::: {.note}`. surprisingly pandoc also emits the correct
docbook tags for `[](#xref)`s, so we can use that too.
* doc/stdenv/meta.chapter.md: document meta.badPlatforms
We don't have any documentation for the `meta.badPlatforms` attribute.
This commit adds documentation for it.
There has been a longstanding ambiguity between `broken` and
`badPlatforms`, which seem to serve overlapping purposes.
This commit adds to the documentation two examples of constraints
which cannot be expressed by `platforms` and `badPlatforms`.
This commit also mentions `NIXPKGS_ALLOW_BROKEN=1` for overriding
`broken`.
without stable ids on headings we cannot generate stable links to these
headings. nrd complains about this, but the current docbook workflow
does not.
a few generated ids remain, mostly in examples and footnotes. most of
the examples are generated by nixdoc (which has since gained MD export
functions, and the MD export does generate IDs).
Closes#16182
This improves the error message
Error: _assignFirst found no valid variant!
which occurred when the set of outputs was not sufficient to set
the various outputDev, outputBin, etc variables. Specifically, this
would mean that "out" is not among the outputs, which is valid for
a derivation.
This changes the message to something like
error: _assignFirst: could not find a non-empty variable to assign to outputDev. The following variables were all unset or empty: dev out.
If you did not define an "out" output, make sure to define all the specific required outputs: define an output for one of the unset variables.
While this isn't a full explanation of what stdenv can and can not do,
I think it's vast improvement over the 0 bits of information that it
used to provide. This at least gives a clue as to what's going on, and
even suggests a fix, although probably multiple such fixes are required
in an instance where someone starts with a no-out derivation from scratch
(and decide to persist).
The nixpkgs manual contains references to both sri hash and explicit
sha256 attributes. This is at best confusing to new users. Since the
final destination is exclusive use of sri hashes, see nixos/rfcs#131,
might as well push new users in that direction gently.
Notable exceptions to sri hash support are builtins.fetchTarball,
cataclysm-dda, coq, dockerTools.pullimage, elixir.override, and
fetchCrate. None, other than builtins.fetchTarball, are fundamentally
incompatible, but all currently accept explicit sha256 attributes as
input. Because adding backwards compatibility is out of scope for this
change, they have been left intact, but migration to sri format has been
made for any using old hash formats.
All hashes have been manually tested to be accurate, and updates were
only made for missing upstream artefacts or bugs.
Promote the `maintainers = with maintainers; [ ]` syntax as that is most common
in nixpkgs, and remove the `nix-env` example which doesn't work like that anymore.
A tricky thing about FreeBSD is that there is no stable ABI across
versions. That means that putting in the version as part of the config
string is paramount.
We have a parsed represenation that separates name versus version to
accomplish this. We include FreeBSD versions 12 and 13 to demonstrate
how it works.
This change mimics existing strip{All,Debug}List variables to
allow special stripping directories just for Target.
The primary use case in mind is gcc where package has to install
both host and target ELFs. They have to be stripped by their own
strip tools accordingly.
Co-authored-by: Rick van Schijndel <Mindavi@users.noreply.github.com>
Co-authored-by: Sandro <sandro.jaeckel@gmail.com>
This commit clarifies that the meaning of the `meta.sourceProvenance`
field is independent of and unaffected by the value of the
`meta.license` field. This is based on the intent of the RFC author
as expressed here:
https://github.com/NixOS/nixpkgs/pull/161098#issuecomment-1081270201
This clarification is added for two reasons:
1. If in the future there should be some disagreement about what
`sourceProvenance` to assign to a package, this may help resolve
the disagreement. Any interpretation of `sourceProvenance` which
is influenced by the `meta.license` is clearly an incorrect
interpretation.
2. If it should turn out that it is impossible to disentangle
`sourceProvenance` from `meta.license`, this would indicate the
need for changes to the `sourceProvenance` scheme. That change
might be as simple as replacing the sentence added by this commit
with some other sentence explaining how the two fields influence
each other.
This commit implements the recommendation made in the paragraph of
this comments which begins with "Please say this explicitly...":
https://github.com/NixOS/nixpkgs/pull/161098#issuecomment-1081309089
this is not an actual sync, but rather the manual taking the leading role.
right now it does not make sense to actually change `patch-shebangs.sh`
as that would cause a rebuild of the entire universe.
we should figure out how to keep them aligned with minimal effort both
in terms of maintenance as well as navigation for readers.
This commit describes the "->" notation for dependency types in
greater detail, and uses g++ to provide examples of all six cases
(although the host->target and target->target examples are a bit
artificial).
It also adds three more rows to the table for the "->*" dependency
types for non-compiler-like packages; these dependency types were
already present in the documentation but the "*" was not really
explained.
Lastly, this commit adds a hyperlink to the table from the place where
it is mentioned in the "specifying dependencies" chapter.
