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.
* doc rendering: add functions to scope explicitly
this especially helps beginners with code readability, since the origin
of names is always immediately visible.
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
Instead of constructing a markdown list in C++ (which involved all sorts
of nasty string literals), export some JSON and assemble it with the
manual build system.
Besides following the precedent set with other dumped data, this is a
better separate of content and presentation; if we decide for example we
want to display this information in a different way, or in a different
section of the manual, it will become much easier to do so.
otherwise the order of found `.md` files will influence if `@docroot@`
is replaced before them being included, which may mess up relative
links.
the weirdest thing about it is that the mess-up happens
deterministically on macOS, but deterministically doesn't happen on
Linux!
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 motivation is as stated in issue #7814: even though the the C++ API
is internal and unstable, people still want it to be well documented for
sake of learning, code review, and other purposes that aren't predicated
on it being stable.
Fixes#7814
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
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 way the links are clearly within the manual (ie not absolute paths),
while allowing snippets to reference the documentation root reliably,
regardless of at which base url they're included.
mdbook-linkcheck is not consistent about its warning setting.
It disables some warnings, but not the warnings about lack of
fragment checking support; hence the extra filtering.
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>
* doc/book.toml: Improve config
- `title` value will be added to the HTML <title> - here</title>
- `git-repository-url` adds a link to the GitHub repo in the top right corner
- `edit-url-template` adds an edit link, inviting contributions
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
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.
this is a quick half-fix for command line examples, as discussed
discussed in [1].
[1]: https://github.com/NixOS/nix/pull/7389
examples which look like this
$ foo bar
baz
are confusing for Unix shell beginners, because it's hard to discern
what is supposed to be entered into the actual command line when the
convention of prefixing `$` is not known, as barely any real-world shell
looks that way any more.
this change prevents selecting the prompt part with the mouse in the
HTML representation of the Nix manual.
it does not prevent selecting the output part of the shell example.
it also does not address that the copy button provided by mdBook takes
the entire sample, including the prompts, into the clipboard.
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).
In addition to consistency, the fancy "Copy to clipboard" button on the
website will copy the prompt character. Retaining the prompt character
would mean having to edit each command after pasting in the terminal.
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.
renaming section headers and changing manually set `id`s will break URLs
in the wild.
this change allows keeping track of all changes to ensure backwards
compatibility.
this simplifies the setup a lot, and avoids weird looking `./file.md`
links showing up.
it also does not show regular URLs any more. currently the command
reference only has few of them, and not showing them in the offline
documentation is hopefully not a big deal.
instead of building more special-case solutions, clumsily preprocessing
the input, or issuing verbal rules on dealing with URLs, should better
be solved sustainably by not rendering relative links in `lowdown`:
https://github.com/kristapsdz/lowdown/issues/105
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>
The current docs are all "how to do things" and no "what is Nix" or "why
are things the way they are".
I see lots of misconception on the wider internet, and I also think we
would benefit from a "living document" to answer some questions people
currently turn to the thesis for.
I think a new section of the manual can address all these issues.
it is out of date, all over the place in level of detail, is really
about `nixpkgs`, and in general instructions should not be part of
a reference manual.
also:
- update redirects and internal links
- use "Nix language" consistently
Before #5150 the copy-to-store phase of the install was idempotent,
but the recursive cp isn't. This is probably baiting a few people
into trying corrective installs that will fail.
Added using the following sed scripts:
- For command-ref/opt-common.md:
s~- `(--?)([^`]+)`~- [`\1\2`]{#opt-\2}~g
- For expressions/builtin-constants.md:
s~- `(builtins\.?)([^`]+)`~- [`\1\2`]{#builtins-\2}~g
- For expressions/advanced-attributes.md
s~^ - `([^`]+)`~ - [`\1`]{#adv-attr-\1}~g
and manually adjusted outputHashAlgo & outputHashMode.
- For glossary.md
s~^ - (`([^`]+)`|(.+)) ?\\~ - [\1]{#gloss-\2\3}\\~g;
s~(gloss-\w+) ~\1-~g
and manually adjusted anchors for Nix expression, user environment, NAR, ∅ and ε.
- For command-ref/env-common.md
s~^ - `([^`]+)`~ - [`\1`]{#env-\1}~g'
Python is only pulled into the build closure by Mercurial, which might end up being removed.
Let’s port the script to jq, which is more likely to stay.
It is now possible to use the following syntax to insert anchors into the text:
[]{#anchor-name}
The anchor will allow linking to the location it is placed by appending #anchor-name to the URL.
Additionally, it is possible to create a link pointing to its own location by adding text between the square brackets:
[`--add-root`]{#opt-add-root}
Add a new `file` fetcher type, which will fetch a plain file over
http(s), or from the local file.
Because plain `http(s)://` or `file://` urls can already correspond to
`tarball` inputs (if the path ends-up with a know archive extension),
the URL parsing logic is a bit convuluted in that:
- {http,https,file}:// urls will be interpreted as either a tarball or a
file input, depending on the extensions of the path part (so
`https://foo.com/bar` will be a `file` input and
`https://foo.com/bar.tar.gz` as a `tarball` input)
- `file+{something}://` urls will be interpreted as `file` urls (with
the `file+` part removed)
- `tarball+{something}://` urls will be interpreted as `tarball` urls (with
the `tarball+` part removed)
Fix#3785
Co-Authored-By: Tony Olagbaiye <me@fron.io>
The produced path is then allowed be imported or utilized elsewhere:
```
assert (43 == import (builtins.toFile "source" "43")); "good"
```
This will still fail on write-only stores.
Requested by ppepino on the Matrix:
https://matrix.to/#/!KqkRjyTEzAGRiZFBYT:nixos.org/$Tb32BS3rVE2BSULAX4sPm0h6CDewX2hClOTGzTC7gwM?via=nixos.org&via=matrix.org&via=nixos.dev
This adds a new command, :bl, which works like :b but also creates
a GC root symlink to the various derivation outputs.
ckie@cookiemonster ~/git/nix -> ./outputs/out/bin/nix repl
Welcome to Nix 2.6.0. Type :? for help.
nix-repl> :l <nixpkgs>
Added 16118 variables.
nix-repl> :b runCommand "hello" {} "echo hi > $out"
This derivation produced the following outputs:
./repl-result-out -> /nix/store/kidqq2acdpi05c4a9mlbg2baikmzik44-hello
[1 built, 0.0 MiB DL]
ckie@cookiemonster ~/git/nix -> cat ./repl-result-out
hi
For each `nix.conf` option, add an empty html node with a unique `id`
that can be used as an anchor target. Also make the name of the option
be a link to that target so that it’s easily discoverable.
We can’t rewrite the whole list as an html definition list like it’s
done for the builtins because these options also appear in a man page,
and the manpage renderer (lowdown) can’t render arbitrary html. But the
hack here allows to keep the manpage and have the links in the html
version.
Fix https://github.com/NixOS/nix/issues/5745
gives 2-5% performance improvement across a board of tests.
LTO is broken when using clang; some libs link fine while others crash
the linker with a segfault in the llvm linker plugin. 🙁
The uninstall instructions used to accidentally remove the nix-darwin
LaunchDaemon, this was dropped. However, the original intent was to
remove the Store volume mounting LaunchDaemon.
Clarify that `/nix` being present after the uninstall is normal and it
will only disappear after a reboot.
Co-authored-by: Travis A. Everett <travis.a.everett@gmail.com>
The multi-user installation on macOS, which is now the only option, has
gotten complicated enough that it discourages some users from checking
Nix out for fear of being left with a "dirty" system. Detailed
uninstallation instructions should make this less of an issue.
The logical implication operator is included in this section but never explained. It might stump new readers with a pretty uncommon operator, and it's never referenced explicitly.
nixpkgs can save a good bit of eval memory with this primop. zipAttrsWith is
used quite a bit around nixpkgs (eg in the form of recursiveUpdate), but the
most costly application for this primop is in the module system. it improves
the implementation of zipAttrsWith from nixpkgs by not checking an attribute
multiple times if it occurs more than once in the input list, allocates less
values and set elements, and just avoids many a temporary object in general.
nixpkgs has a more generic version of this operation, zipAttrsWithNames, but
this version is only used once so isn't suitable for being the base of a new
primop. if it were to be used more we should add a second primop instead.
