This is generally a fine practice: Putting implementations in headers
makes them harder to read and slows compilation. Unfortunately it is
necessary for templates, but we can ameliorate that by putting them in a
separate header. Only files which need to instantiate those templates
will need to include the header with the implementation; the rest can
just include the declaration.
This is now documenting in the contributing guide.
Also, it just happens that these polymorphic serializers are the
protocol agnostic ones. (Worker and serve protocol have the same logic
for these container types.) This means by doing this general template
cleanup, we are also getting a head start on better indicating which
code is protocol-specific and which code is shared between protocols.
While this is not actually a notion in the implementation, it is
explicitly described in the thesis and quite important for understanding
how the store works.
Co-authored-by: John Ericson <git@JohnEricson.me>
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Introduce what substituters "are" in the configuration option entry.
Remove arbitrary line breaks for easier editing in the future.
Link glossary some more.
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Co-authored-by: John Ericson <git@JohnEricson.me>
packages and configurations are not really a concept in Nix or the Nix language. the idea of transforming files into other files clearly captures what it's all about, and the new phrasing should make the term "derivation" more obvious both in terms of meaning and origin.
Add support to --list-generations
as another way to say
nix-env --profile /nix/var/nix/profiles/per-user/$USER/channels --list-generations
the way we did for nix-channel --rollback [generation id]
The primop `builtins.replaceStrings` currently always strictly evaluates the
replacement strings, however time and space are wasted for their computation
if the corresponding pattern do not occur in the input string. This commit
makes the evaluation of the replacement strings lazy by deferring their
evaluation to when the corresponding pattern are matched and memoize the result
for efficient retrieval on subsequent matches.
The testcases for replaceStrings was updated to check for lazy evaluation
of the replacements. A note was also added in the release notes to
document the behavior change.
This adds a new configuration option to Nix, `always-allow-substitutes`,
whose effect is simple: it causes the `allowSubstitutes` attribute in
derivations to be ignored, and for substituters to always be used.
This is extremely valuable for users of Nix in CI, where usually
`nix-build-uncached` is used. There, derivations which disallow
substitutes cause headaches as the inputs for building already-cached
derivations need to be fetched to spuriously rebuild some simple text
file.
This option should be a good middle-ground, since it doesn't imply
rebuilding the world, such as the approach I took in
https://github.com/NixOS/nixpkgs/pull/221048
it's more likely for readers to find it right there.
this also slightly rewords examples to make them stand out better.
in the long run there probably needs to be a dedicated section on formal syntax, and better highlighting of examples.
e.g. nix-env -e subversion => nix-env --uninstall subversion
The aim is to make the documentation less cryptic for newcomers and the
long options are more self-documenting.
The change was made with the following script:
<https://github.com/aschmolck/convert-short-nix-opts-to-long-ones>
and sanity checked visually.
This gives some more context and should clarify why it works that way.
Also link it from the section on `NIX_USER_CONF_FILES`.
Co-authored-by: John Ericson <git@JohnEricson.me>
`/etc/bash.bashrc` is backed up as `/etc/bash.bashrc.backup-before-nix`,
but since other changes might have been introduced in the meantime we can't
just tell the user to revert.
add anchor to `builtins.derivation` and list some built-in functions that are
exposed in the global scope.
I decided not to list everything, because we probably don't want to
encourage people using them that way.
it's probably better not to show the manifest file documentation in the
command-specific pages, because these are implementation details that are not really practically useful.
this means no additional hassle for building the manual, but clutters
the table of contents a bit.
placed in a subsection of the binary install, the instructions are hard
to find. putting them in a separate page that is shown in the table of
contents should make it easier for users to find what they need when
they need it.
- Create a glossary entry for experimental features.
- Have the man page experimental feature notice link `nix-commmand`.
(Eventually this should be programmed, based on whether the command is
experimental, and if so what experimental feature does it depend on.)
- Document which installables depend on which experimental features.
I tried to use the same style (bold warning and block quote) that the
top of the man page uses.
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
This function returns true or false depending on whether the Nix client
is trusted or not. Mostly relevant when speaking to a remote store with
a daemon.
We include this information in `nix ping store` and `nix doctor`
Co-Authored-By: John Ericson <John.Ericson@Obsidian.Systems>
They are put in the manual separate pages under the new overarching
description of experimental features.
The settings page just lists the valid experimental feature names (so
people know what a valid setting entry looks like), with links to those
pages. It doesn't attempt to describe each experimental feature as that
is too much information for the configuration settings section.
Add a page explaining what “experimental features” are, when and how they should be used
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
Co-authored-by: Eelco Dolstra <edolstra@gmail.com>
Co-authored-by: John Ericson <John.Ericson@Obsidian.Systems>
the semantics are not explained in the referenced section any more, they
have been moved to the documentation for common options in the new CLI [0].
[0]: 703d863a48
Documentation on "classic" commands with many sub-commands are
notoriously hard to discover due to lack of overview and anchor links.
Additionally the information on common options and environment variables
is not accessible offline in man pages, and therefore often overlooked
by readers.
With this change, each sub-command of nix-store and nix-env gets its
own page in the manual (listed in the table of contents), and each own
man page.
Also, man pages for each subcommand now (again) list common options
and environment variables. While this makes each page quite long and
some common parameters don't apply, this should still make it easier
to navigate as that additional information was not accessible on the
command line at all.
It is now possible to run 'nix-store --<subcommand> --help` to display
help pages for the given subcommand.
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
This provides a platform-independent way to configure the SSL
certificates file in the Nix daemon. Previously we provided
instructions for overriding the environment variable in launchd, but
that obviously doesn't work with systemd. Now we can just tell users
to add
ssl-cert-file = /etc/ssl/my-certificate-bundle.crt
to their nix.conf.
Add the --base64 and --sri flags for the Base64 and SRI format output.
Add the --base16 flag to explicitly specify the hexadecimal format.
Add the --to-base64 and --to-sri flag to convert a hash to the above
mentioned format.
the term was hard to discover, as its definition and explanation were in
a very long document lacking an overview section.
search did not help because it occurs so often.
- clarify wording in the definition
- add an overview of installable types
- add "installable" to glossary
- link to definition from occurrences of the term
- be more precise about where store derivation outputs are processed
- installable Nix expressions must evaluate to a derivation
Co-authored-by: Adam Joseph <54836058+amjoseph-nixpkgs@users.noreply.github.com>
The release notes document the change in behavior, I don't include it
here so there is no risk to it getting out of sync.
> Motivation
>> Plumbing CLI should be simple
Store derivation installations are intended as "plumbing": very simple
utilities for advanced users and scripts, and not what regular users
interact with. (Similarly, regular Git users will use branch and tag
names not explicit hashes for most things.)
The plumbing CLI should prize simplicity over convenience; that is its
raison d'etre. If the user provides a path, we should treat it the same
way not caring what sort of path it is.
>> Scripting
This is especially important for the scripting use-case. when arbitrary
paths are sent to e.g. `nix copy` and the script author wants consistent
behavior regardless of what those store paths are. Otherwise the script
author needs to be careful to filter out `.drv` ones, and then run `nix
copy` again with those paths and `--derivation`. That is not good!
>> Surprisingly low impact
Only two lines in the tests need changing, showing that the impact of
this is pretty light.
Many command, like `nix log` will continue to work with just the
derivation passed as before. This because we used to:
- Special case the drv path and replace it with it's outputs (what this
gets rid of).
- Turn those output path *back* into the original drv path.
Now we just skip that entire round trip!
> Context
Issue #7261 lays out a broader vision for getting rid of `--derivation`,
and has this as one of its dependencies. But we can do this with or
without that.
`Installable::toDerivations` is changed to handle the case of a
`DerivedPath::Opaque` ending in `.drv`, which is new: it simply doesn't
need to do any extra work in that case. On this basis, commands like
`nix {show-derivation,log} /nix/store/...-foo.drv` still work as before,
as described above.
When testing older daemons, the post-build-hook will be run against the
old CLI, so we need the old version of the post-build-hook to support
that use-case.
Co-authored-by: Travis A. Everett <travis.a.everett@gmail.com>
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
- `nixpkgsFor` does all of native, static, cross, and the different stdenvs.
- The main Nix derivation is no longer duplicated for static.
- DRY nixpkgs.lib and lib.genAttrs calls.
- Refer to current version in readme
- Split into flakes and non-flakes section
- Change order to move nix-build to the end, since people often start
with it in the beginning.
- Use proper "Note" syntax
- Add notes about editor integration
- Move information about target platforms and stdenvs into separate
sections
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
Co-authored-by: Alexander Bantyev <alexander.bantyev@tweag.io>
Co-authored-by: Théophane Hufschmitt <theophane.hufschmitt@tweag.io>
XDG Base Directory is a standard for locations for storing various
files. Nix has a few files which seem to fit in the standard, but
currently use a custom location directly in the user's ~, polluting
it:
- ~/.nix-profile
- ~/.nix-defexpr
- ~/.nix-channels
This commit adds a config option (use-xdg-base-directories) to follow
the XDG spec and instead use the following locations:
- $XDG_STATE_HOME/nix/profile
- $XDG_STATE_HOME/nix/defexpr
- $XDG_STATE_HOME/nix/channels
If $XDG_STATE_HOME is not set, it is assumed to be ~/.local/state.
Co-authored-by: Théophane Hufschmitt <7226587+thufschmitt@users.noreply.github.com>
Co-authored-by: Tim Fenney <kodekata@gmail.com>
Co-authored-by: pasqui23 <pasqui23@users.noreply.github.com>
Co-authored-by: Artturin <Artturin@artturin.com>
Co-authored-by: John Ericson <Ericson2314@Yahoo.com>
`clang11StdenvPackages` does not exist
```
│ └───x86_64-linux
│ ├───ccacheStdenv: development environment 'nix'
│ ├───clang11Stdenv: development environment 'nix'
│ ├───clangStdenv: development environment 'nix'
│ ├───default: development environment 'nix'
│ ├───gccStdenv: development environment 'nix'
│ ├───libcxxStdenv: development environment 'nix'
│ └───stdenv: development environment 'nix'
```
Commit 14bc3ce3d6 (0.13~43) changed the
timestamps in the Nix store from 0 to 1. Update the nix-store man
page to match.
Signed-off-by: Anders Kaseorg <andersk@mit.edu>
Allows checking directory entry type of a single file/directory.
This was added to optimize the use of `builtins.readDir` on some
filesystems and operating systems which cannot detect this information
using POSIX's `readdir`.
Previously `builtins.readDir` would eagerly use system calls to lookup
these filetypes using other interfaces; this change makes these
operations lazy in the attribute values for each file with application
of `builtins.readFileType`.
this form is much easier to maintain (also with minimal diffs), and
allows for more details on each operator.
this change a purely mechanical transformation, without changing any contents.
Adds a new boolean structured attribute
`outputChecks.<output>.unsafeDiscardReferences` which disables scanning
an output for runtime references.
__structuredAttrs = true;
outputChecks.out.unsafeDiscardReferences = true;
This is useful when creating filesystem images containing their own embedded Nix
store: they are self-contained blobs of data with no runtime dependencies.
Setting this attribute requires the experimental feature
`discard-references` to be enabled.
This makes 'nix develop' set the Linux personality in the same way
that the actual build does, allowing a command like 'nix develop
nix#devShells.i686-linux.default' on x86_64-linux to work correctly.
First, logic is consolidated in the shell script instead of being spread
between them and makefiles. That makes understanding what is going on a
little easier.
This would not be super interesting by itself, but it gives us a way to
debug tests more easily. *That* in turn I hope is much more compelling.
See the updated manual for details.
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
Co-authored-by: Eelco Dolstra <edolstra@gmail.com>
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
this avoids incorrect rendering on the man pages, since `lowdown`
neither parses the anchor syntax nor HTML.
this should rather be fixed in lowdown, as adding more anchors
would otherwise produce ever more noise and error-prone repetition.
* docs: Use secret-key-files when demonstrating post-build-hooks
The docs used to recommend calling `nix store sign` in a post-build
hook, but on more recent versions of nix, this results in unsigned
store paths being copied into binary caches. See
https://github.com/NixOS/nix/issues/6960 for details.
Instead, use the `secret-key-files` config option, which signs all
locally-built derivations with the private key.
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
These only functioned if a very narrow combination of conditions held:
- The result path does not yet exist (--check did not result in
repeated builds), AND
- The result path is not available from any configured substituters, AND
- No remote builders that can build the path are available.
If any of these do not hold, a derivation would be built 0 or 1 times
regardless of the repeat option. Thus, remove it to avoid confusion.
after discussing this with multiple people, I'm convinced that "build
task" is more precise: a derivation is not an action, but inert until it
is built. also it's easier to pronounce.
proposal: use "build task" for the generic concept "description of how
to derive new files from the contents of existing files". then it will
be easier to distinguish what we mean by "derivation" (a specific data
structure and Nix language value type) and "store derivation" (a
serialisation of a derivation into a file in the Nix store).
Specifically, explain why Nix does not _re_evaluate paths during a
`nix repl` session. This is a thing that bit me while playing around
with paths and antiquotation in `nix repl` while reading the Nix
language tutorial at https://nix.dev/tutorials/nix-language.
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
Mainly:
- Try to triangulate between narrative that framed this as
a new/easy process and the need for a reference that will
not quickly grow stale.
- Fix a ~continuity issue where the text was talking about
"your Cachix cache" before saying that you'd need to make
a Cachix cache to enable the installer tests.
- Adopt suggestion on titling, and nest subtitles in the
installer test section.
Nix veterans intuitively know what the following terms mean. They are
used in several places in the nix documentation, but never defined:
- local store
- remote store
- binary cache
- substituter
In particular, I found the last two terms to be confusingly similar.
Let's give definitions for them.
this is not as compact any more, but it more closely resembles the
chapter structure, and clearly shows that the closure property is the
key idea on which most of Nix operates.
clarify that we are copying between different stores. we have not
introduced that notion or why it would be interesting, but for now it
should be fine to keep it in context of the store directory.
we could move that later to a more detailed explanation of different
store types.
at this level of abstraction we do not really care about build instructions or what they are, and also build instructions including their arguments really amount to the build task.
group description of data instead of spreading it across the section.
that should help direct skimming. as it turns out, people do not
actually read any of that.
this leaves open implementation details, especially about store paths
and file system objects, and allows explaining them together were it is
more appropriate. also leaves room to carefully introduce the key
insight behind Nix: applying results from programming language theory to
the operating system paradigm of files and processes.
while this may eventually introduce ugly diffs, the table will now
render readably on the terminal (e.g. for `man nix` or `nix --help`)
without further intervention.
while it appears a bit much for the overview, this way we set the stage
for going directly into data types when describing the store, instead of
first having to say what build tasks are and how they relate to build
plans.
this displays correct composition again. build inputs and build results
are not part of build plans in terms of data objects.
also this is a much less complicated setup. this will be the first
impression of architecture, and we want to get it right.
convention: describe every data type in prose, and illustrate with
a class diagram, and a textual representation of an abstract
data type.
right now we save ourselves the trouble of doing class diagrams, we can
add them later. but they are important.
use file Contents instead of Data, as that flows more naturally in the
prose.
simplify explanation of the idea behind scanning for store paths
remove references to unfinished sections.
attempt to explain used and documented terminology, as well as how
the declarative programming paradigm relates to building software.
in the future one could highlight encouraged terms to shape future
material into higher consistency.
the diagram is a first approximation and only covers that same section.
of course there is much more going on, and other features should at some
point also be illustrated.
we also have to think about presentation format and technicalities
behind it. the manual has to render to `man`, but we may want something
more refined for web view.
there should be a meta section for each chapter to give motivation of
the presented structure. the structure itself is visible from the table
of contents.
idea: sections could be read in different orders by linking them in
different ways (e.g. depth-first or breadth-first). adding hard-coded
transitions makes that confusing.
trying to capture alternative terms in one go here, mirroring everyday
use:
derivation - build plan
realise - execute build
there will be more of that sort.
The idea and most of the execution are @fricklerhandwerk's. I changed a
few things best I could based on @edolstra's corrections, and a Bazel
glossary.
Valentin Gagarin <valentin@fricklerhandwerk.de>
