For frameworks it's important that structures are as lazy as possible
to prevent infinite recursions, performance issues and errors that
aren't related to the thing to evaluate. As a consequence, they have
to emit more attributes than strictly (sic) necessary.
However, these attributes with empty values are not useful to the user
so we omit them.
No other getDefaultFlakeAttrPaths implementation has this trailing dot,
and the dot can show up in error messages like:
error: flake '...' does not provide attribute 'packages.x86_64-linux.', ...
Avoid needless work and throwing away invariants.
These conversions date back to when `StorePath` was in Rust and there
were issues with it missing utility methods.
Rather than using `/nix/var/nix/{profiles,gcroots}/per-user/`, put the user
profiles and gcroots under `$XDG_DATA_DIR/nix/{profiles,gcroots}`.
This means that the daemon no longer needs to manage these paths itself
(they are fully handled client-side). In particular, it doesn’t have to
`chown` them anymore (removing one need for root).
This does change the layout of the gc-roots created by nix-env, and is
likely to break some stuff, so I’m not sure how to properly handle that.
Instead of needing to run `nix show-config --json | jq -r
'."warn-dirty".value'` to view the value of `warn-dirty`, you can now
run `nix show-config warn-dirty`.
`DerivedPath::Built` and `DerivationGoal` were previously using a
regular set with the convention that the empty set means all outputs.
But it is easy to forget about this rule when processing those sets.
Using `OutputSpec` forces us to get it right.
Prior to this change, we had a bunch of ad-hoc string manipulation code
scattered around. This made it hard to figure out what data model for
string contexts is.
Now, we still store string contexts most of the time as encoded strings
--- I was wary of the performance implications of changing that --- but
whenever we parse them we do so only through the
`NixStringContextElem::parse` method, which handles all cases. This
creates a data type that is very similar to `DerivedPath` but:
- Represents the funky `=<drvpath>` case as properly distinct from the
others.
- Only encodes a single output, no wildcards and no set, for the
"built" case.
(I would like to deprecate `=<path>`, after which we are in spitting
distance of `DerivedPath` and could maybe get away with fewer types, but
that is another topic for another day.)
This has the same goal as b13fd4c58e81b2b2b0d72caa5ce80de861622610,but
achieves it in a different way in order to not break
`nix why-depends --derivation`.
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.
why-depends assumed that we knew the output path of the second argument.
For CA derivations, we might not know until it's built. One way to solve
this would be to build the second installable to get the output path.
In this case we don't need to, though. If the first installable (A)
depends on the second (B), then getting the store path of A will
necessitate having the store path B. The contrapositive is, if the store
path of B is not known (i.e. it's a CA derivation which hasn't been
built), then A does not depend on B.
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).
I just had a colleague get confused by the previous phrase for good
reason. "valid" sounds like an *objective* criterion, e.g. and *invalid
signature* would be one that would be trusted by no one, e.g. because it
misformatted or something.
What is actually going is that there might be a signature which is
perfectly valid to *someone else*, but not to the user, because they
don't trust the corresponding public key. This is a *subjective*
criterion, because it depends on the arbitrary and personal choice of
which public keys to trust.
I therefore think "trustworthy" is a better adjective to use. Whether
something is worthy of trust is clearly subjective, and then "trust"
within that word nicely evokes `trusted-public-keys` and friends.
Stdenv sets this to a bash that doesn't have readline/completion
support, so running 'nix (develop|shell)' inside a 'nix develop' gives
you a crippled shell. So let's just ignore the derivation's $SHELL.
This could break interactive use of build phases that use $SHELL, but
they appear to be fairly rare.
This was caused by -L calling setLogFormat() again, which caused the
creation of a new progress bar without destroying the old one. So we
had two progress bars clobbering each other.
We should change 'logger' to be a smart pointer, but I'll do that in a
future PR.
Fixes#6931.
Makes `printValueAsJSON` not copy paths to the store for `nix eval
--json`, `nix-instantiate --eval --json` and `nix-env --json`.
Fixes https://github.com/NixOS/nix/issues/5612
Defers completion of flake inputs until the whole command line is parsed
so that we know what flakes we need to complete the inputs of.
Previously, `nix build flake --update-input <Tab>` always behaved like
`nix build . --update-input <Tab>`.
Allow `nix build flake1 flake2 --update-input <Tab>` to complete the
inputs of both flakes.
Also do tilde expansion so that `nix build ~/flake --update-input <Tab>`
works.
If a package's attribute path, description or name contains matches for any of the
regexes specified via `-e` or `--exclude` that package is excluded from
the final output.
To quote Eelco in #5867:
> Unfortunately we can't do
>
> evalSettings.pureEval.setDefault(false);
>
> because then we have to do the same in main.cc (where
> pureEval is set to true), and that would allow pure-eval
> to be disabled globally from nix.conf.
Instead, a command should specify that it should be impure by
default. Then, `evalSettings.pureEval` will be set to `false;` unless
it's overridden by e.g. a CLI flag.
In that case it's IMHO OK to be (theoretically) able to override
`pure-eval` via `nix.conf` because it doesn't have an effect on commands
where `forceImpureByDefault` returns `false` (i.e. everything where pure
eval actually matters).
Closes#5867
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>
If experimental feature "flakes" is enabled, args passed to `nix repl`
will now be considered flake refs and imported using the existing
`:load-flake` machinery.
In addition, `:load-flake` now supports loading flake fragments.
Ensures the logger is stopped on exit in legacy commands. Without this,
when using `nix-build --log-format bar` and stopping nix with CTRL+C,
the bar is not cleared from the screen.
'nix profile install' will now install all outputs listed in the
package's meta.outputsToInstall attribute, or all outputs if that
attribute doesn't exist. This makes it behave consistently with
nix-env. Fixes#6385.
Furthermore, for consistency, all other 'nix' commands do this as
well. E.g. 'nix build' will build and symlink the outputs in
meta.outputsToInstall, defaulting to all outputs. Previously, it only
built/symlinked the first output. Note that this means that selecting
a specific output using attrpath selection (e.g. 'nix build
nixpkgs#libxml2.dev') no longer works. A subsequent PR will add a way
to specify the desired outputs explicitly.
after #6218 `Symbol` no longer confers a uniqueness invariant on the
string it wraps, it is now possible to create multiple symbols that
compare equal but whose string contents have different addresses. this
guarantee is now only provided by `SymbolIdx`, leaving `Symbol` only as
a string wrapper that knows about the intricacies of how symbols need to
be formatted for output.
this change renames `SymbolIdx` to `Symbol` to restore the previous
semantics of `Symbol` to that name. we also keep the wrapper type and
rename it to `SymbolStr` instead of returning plain strings from lookups
into the symbol table because symbols are formatted for output in many
places. theoretically we do not need `SymbolStr`, only a function that
formats a string for output as a symbol, but having to wrap every symbol
that appears in a message into eg `formatSymbol()` is error-prone and
inconvient.
this slightly increases the amount of memory used for any given symbol, but this
increase is more than made up for if the symbol is referenced more than once in
the EvalState that holds it. on average every symbol should be referenced at
least twice (once to introduce a binding, once to use it), so we expect no
increase in memory on average.
symbol tables are limited to 2³² entries like position tables, and similar
arguments apply to why overflow is not likely: 2³² symbols would require as many
string instances (at 24 bytes each) and map entries (at 24 bytes or more each,
assuming that the map holds on average at most one item per bucket as the docs
say). a full symbol table would require at least 192GB of memory just for
symbols, which is well out of reach. (an ofborg eval of nixpks today creates
less than a million symbols!)
Pos objects are somewhat wasteful as they duplicate the origin file name and
input type for each object. on files that produce more than one Pos when parsed
this a sizeable waste of memory (one pointer per Pos). the same goes for
ptr<Pos> on 64 bit machines: parsing enough source to require 8 bytes to locate
a position would need at least 8GB of input and 64GB of expression memory. it's
not likely that we'll hit that any time soon, so we can use a uint32_t index to
locate positions instead.
only file and line of the returned position were ever used, it wasn't actually
used a position. as such we may as well use a path+int pair for only those two
values and remove a use of Pos that would not work well with a position table.
a future commit will remove the ability to convert the symbol type used in
bindings to strings. since we only have two users we can inline the error check.
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
In particular, this means that 'nix eval` (which uses toValue()) no
longer auto-calls functions or functors (because
AttrCursor::findAlongAttrPath() doesn't).
Fixes#6152.
Also use ref<> in a few places, and don't return attrpaths from
getCursor() because cursors already have a getAttrPath() method.
Impure derivations are derivations that can produce a different result
every time they're built. Example:
stdenv.mkDerivation {
name = "impure";
__impure = true; # marks this derivation as impure
outputHashAlgo = "sha256";
outputHashMode = "recursive";
buildCommand = "date > $out";
};
Some important characteristics:
* This requires the 'impure-derivations' experimental feature.
* Impure derivations are not "cached". Thus, running "nix-build" on
the example above multiple times will cause a rebuild every time.
* They are implemented similar to CA derivations, i.e. the output is
moved to a content-addressed path in the store. The difference is
that we don't register a realisation in the Nix database.
* Pure derivations are not allowed to depend on impure derivations. In
the future fixed-output derivations will be allowed to depend on
impure derivations, thus forming an "impurity barrier" in the
dependency graph.
* When sandboxing is enabled, impure derivations can access the
network in the same way as fixed-output derivations. In relaxed
sandboxing mode, they can access the local filesystem.
Rather than having four different but very similar types of hashes, make
only one, with a tag indicating whether it corresponds to a regular of
deferred derivation.
This implies a slight logical change: The original Nix+multiple-outputs
model assumed only one hash-modulo per derivation. Adding
multiple-outputs CA derivations changed this as these have one
hash-modulo per output. This change is now treating each derivation as
having one hash modulo per output.
This obviously means that we internally loose the guaranty that
all the outputs of input-addressed derivations have the same hash
modulo. But it turns out that it doesn’t matter because there’s nothing
in the code taking advantage of that fact (and it probably shouldn’t
anyways).
The upside is that it is now much easier to work with these hashes, and
we can get rid of a lot of useless `std::visit{ overloaded`.
Co-authored-by: John Ericson <John.Ericson@Obsidian.Systems>
Before this change, processLine always uses the first character
as the start of the line. This cause whitespaces to matter at the
beginning of the line whereas it does not matter anywhere else.
This commit trims leading white spaces of the string line so that
subsequent operations can be performed on the string without explicitly
tracking starting and ending indices of the string.
1. `DerivationOutput` now as the `std::variant` as a base class. And the
variants are given hierarchical names under `DerivationOutput`.
In 8e0d0689be @matthewbauer and I
didn't know a better idiom, and so we made it a field. But this sort
of "newtype" is anoying for literals downstream.
Since then we leaned the base class, inherit the constructors trick,
e.g. used in `DerivedPath`. Switching to use that makes this more
ergonomic, and consistent.
2. `store-api.hh` and `derivations.hh` are now independent.
In bcde5456cc I swapped the dependency,
but I now know it is better to just keep on using incomplete types as
much as possible for faster compilation and good separation of
concerns.
Don’t try and assume that we know the output paths when we’ve just built
with `--dry-run`. Instead make `--dry-run` follow a different code path
that won’t assume the knowledge of the output paths at all.
Fix#6275
This changes was taken from dynamic derivation (#4628). It` somewhat
undoes the refactors I first did for floating CA derivations, as the
benefit of hindsight + requirements of dynamic derivations made me
reconsider some things.
They aren't to consequential, but I figured they might be good to land
first, before the more profound changes @thufschmitt has in the works.
Continue progress on #5729.
Just as I hoped, this uncovered an issue: the daemon protocol is missing
a way to query build logs. This doesn't effect `unix://`, but does
effect `ssh://`. A FIXME is left for this, so we come back to it later.
Starts progress on #5729.
The idea is that we should not have these default methods throwing
"unimplemented". This is a small step in that direction.
I kept `addTempRoot` because it is a no-op, rather than failure. Also,
as a practical matter, it is called all over the place, while doing
other tasks, so the downcasting would be annoying.
Maybe in the future I could move the "real" `addTempRoot` to `GcStore`,
and the existing usecases use a `tryAddTempRoot` wrapper to downcast or
do nothing, but I wasn't sure whether that was a good idea so with a
bias to less churn I didn't do it yet.
This is useful whenever we want to evaluate something to a store path
(e.g. in get-drvs.cc).
Extracted from the lazy-trees branch (where we can require that a
store path must come from a store source tree accessor).
On Nix 2.6 the output of `nix why-depends --all` seems to be somewhat
off:
$ nix why-depends /nix/store/kn47hayxab8gc01jhr98dwyywbx561aq-nixos-system-roflmayr-21.11.20220207.6c202a9.drv /nix/store/srn5jbs1q30jpybdmxqrwskyny659qgc-nix-2.6.drv --derivation --extra-experimental-features nix-command --all
/nix/store/kn47hayxab8gc01jhr98dwyywbx561aq-nixos-system-roflmayr-21.11.20220207.6c202a9.drv
└───/nix/store/g8bpgfjhh5vxrdq0w6r6s64f9kkm9z6c-etc.drv
│ └───/nix/store/hm0jmhp8shbf3cl846a685nv4f5cp3fy-nspawn-inst.drv
| [...]
└───/nix/store/2d6q3ygiim9ijl5d4h0qqx6vnjgxywyr-system-units.drv
└───/nix/store/dil014y1b8qyjhhhf5fpaah5fzdf0bzs-unit-systemd-nspawn-hydra.service.drv
└───/nix/store/a9r72wwx8qrxyp7hjydyg0gsrwnn26zb-activate.drv
└───/nix/store/99hlc7i4gl77wq087lbhag4hkf3kvssj-nixos-system-hydra-21.11pre-git.drv
Please note that `[...]-system-units.drv` is supposed to be a direct
child of `[...]-etc.drv`.
The reason for that is that each new level printed by `printNode` is
four spaces off in comparison to `nix why-depends --precise` because the
recursive `printNode()` only prints the path and not the `tree*`-chars in
the case of `--precise` and in this format the path is four spaces further
indented, i.e. on a newline, but on the same level as the path's children, i.e.
/nix/store/kn47hayxab8gc01jhr98dwyywbx561aq-nixos-system-roflmayr-21.11.20220207.6c202a9.drv
└───/: …1-p8.drv",["out"]),("/nix/store/g8bpgfjhh5vxrdq0w6r6s64f9kkm9z6c-etc.drv",["out"]),("/nix/store/…
→ /nix/store/g8bpgfjhh5vxrdq0w6r6s64f9kkm9z6c-etc.drv
As you can see `[...]-etc.drv` is a direct child of the root, but four
spaces indented. This logic was directly applied to the code-path with
`precise=false` which resulted in `tree*` being printed four spaces too
deep.
In case of no `--precise`, `hits[hash]` is empty and the path itself
should be printed rather than hits using the same logic as for `hits[hash]`.
With this fix, the output looks correct now:
/nix/store/kn47hayxab8gc01jhr98dwyywbx561aq-nixos-system-roflmayr-21.11.20220207.6c202a9.drv
└───/nix/store/g8bpgfjhh5vxrdq0w6r6s64f9kkm9z6c-etc.drv
├───/nix/store/hm0jmhp8shbf3cl846a685nv4f5cp3fy-nspawn-inst.drv
| [...]
└───/nix/store/2d6q3ygiim9ijl5d4h0qqx6vnjgxywyr-system-units.drv
└───/nix/store/dil014y1b8qyjhhhf5fpaah5fzdf0bzs-unit-systemd-nspawn-hydra.service.drv
└───/nix/store/a9r72wwx8qrxyp7hjydyg0gsrwnn26zb-activate.drv
└───/nix/store/99hlc7i4gl77wq087lbhag4hkf3kvssj-nixos-system-hydra-21.11pre-git.drv
Bundlers are now responsible for correctly handling their inputs which
are no longer constrained to be (Drv->Drv)->Drv->Drv, but can be of
type (attrset->Drv)->attrset->Drv.
we'll retain the old coerceToString interface that returns a string, but callers
that don't need the returned value to outlive the Value it came from can save
copies by using the new interface instead. for values that weren't stringy we'll
pass a new buffer argument that'll be used for storage and shouldn't be
inspected.
Robert Hensing
Yorick
Maximilian Bosch
mei (ckie)
Linus Heckemann