Store paths are only allowed to contain a limited subset of the
alphabet, which doesn’t include `!`. So don’t create lockfiles that
contain this `!` character as that would otherwise confuse (and break)
the gc.
Fix#5176
With this, we don't have to copy the entire .drv closure to the
destination store ahead of time (or at all). Instead, buildPaths()
reads .drv files from the eval store and copies inputSrcs to the
destination store if it needs to build a derivation.
Issue #5025.
Fill `NIX_CONFIG` with the value of the current Nix configuration before
calling the post-build-hook.
That way the whole configuration (including the possible
`experimental-features`, a possibly `--store` option or whatever) will
be made available to the hook
This is needed to push the adoption of structured attrs[1] forward. It's
now checked if a `__json` exists in the environment-map of the derivation
to be openend in a `nix-shell`.
Derivations with structured attributes enabled also make use of a file
named `.attrs.json` containing every environment variable represented as
JSON which is useful for e.g. `exportReferencesGraph`[2]. To
provide an environment similar to the build sandbox, `nix-shell` now
adds a `.attrs.json` to `cwd` (which is mostly equal to the one in the
build sandbox) and removes it using an exit hook when closing the shell.
To avoid leaking internals of the build-process to the `nix-shell`, the
entire logic to generate JSON and shell code for structured attrs was
moved into the `ParsedDerivation` class.
[1] https://nixos.mayflower.consulting/blog/2020/01/20/structured-attrs/
[2] https://nixos.org/manual/nix/unstable/expressions/advanced-attributes.html#advanced-attributes
This avoids an ambiguity where the `StorePathWithOutputs { drvPath, {}
}` could mean "build `brvPath`" or "substitute `drvPath`" depending on
context.
It also brings the internals closer in line to the new CLI, by
generalizing the `Buildable` type is used there and makes that
distinction already.
In doing so, relegate `StorePathWithOutputs` to being a type just for
backwards compatibility (CLI and RPC).
This separates the scheduling logic (including simple hook pathway) from
the local-store needing code.
This should be the final split for now. I'm reasonably happy with how
it's turning out, even before I'm done moving code into
`local-derivation-goal`. Benefits:
1. This will help "witness" that the hook case is indeed a lot simpler,
and also compensate for the increased complexity that comes from
content-addressed derivation outputs.
2. It also moves us ever so slightly towards a world where we could use
off-the-shelf storage or sandboxing, since `local-derivation-goal`
would be gutted in those cases, but `derivation-goal` should remain
nearly the same.
The new `#if 0` in the new files will be deleted in the following
commit. I keep it here so if it turns out more stuff can be moved over,
it's easy to do so in a way that preserves ordering --- and thus
prevents conflicts.
N.B.
```sh
git diff HEAD^^ --color-moved --find-copies-harder --patience --stat
```
makes nicer output.
This field used to be a `BasicDerivation`, but this `BasicDerivation`
was downcasted to a `Derivation` when needed (implicitely or not), so we
might as well make it a full `Derivation` and upcast it when needed.
This also allows getting rid of a weird duplication in the way we
compute the static output hashes for the derivation. We had to
do it differently and in a different place depending on whether the
derivation was a full derivation or just a basic drv, but we can now do
it unconditionally on the full derivation.
Fix#4559
- Pass it the name of the outputs rather than their output paths (as
these don't exist for ca derivations)
- Get the built output paths from the remote builder
- Register the new received realisations
That way we
1. Don't have to recompute them several times
2. Can compute them in a place where we know the type of the parent
derivation, meaning that we don't need the casting dance we had before
Once a build is done, get back to the original derivation, and register
all the newly built outputs for this derivation.
This allows Nix to work properly with derivations that don't have all
their build inputs available − thus allowing garbage collection and
(once it's implemented) binary substitution
Fix a mismatch in the errors thrown when a needed output was missing
from an input derivation that was leading to a wrong and quite misleading error
message
Changes:
* The divider lines are gone. These were in practice a bit confusing,
in particular with --show-trace or --keep-going, since then there
were multiple lines, suggesting a start/end which wasn't the case.
* Instead, multi-line error messages are now indented to align with
the prefix (e.g. "error: ").
* The 'description' field is gone since we weren't really using it.
* 'hint' is renamed to 'msg' since it really wasn't a hint.
* The error is now printed *before* the location info.
* The 'name' field is no longer printed since most of the time it
wasn't very useful since it was just the name of the exception (like
EvalError). Ideally in the future this would be a unique, easily
googleable error ID (like rustc).
* "trace:" is now just "…". This assumes error contexts start with
something like "while doing X".
Example before:
error: --- AssertionError ---------------------------------------------------------------------------------------- nix
at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix
6|
7| x = assert false; 1;
| ^
8|
assertion 'false' failed
----------------------------------------------------- show-trace -----------------------------------------------------
trace: while evaluating the attribute 'x' of the derivation 'hello-2.10'
at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix
191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) {
192| name = "${attrs.pname}-${attrs.version}";
| ^
193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
Example after:
error: assertion 'false' failed
at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix
6|
7| x = assert false; 1;
| ^
8|
… while evaluating the attribute 'x' of the derivation 'hello-2.10'
at: (192:11) in file: /home/eelco/Dev/nixpkgs/pkgs/stdenv/generic/make-derivation.nix
191| // (lib.optionalAttrs (!(attrs ? name) && attrs ? pname && attrs ? version)) {
192| name = "${attrs.pname}-${attrs.version}";
| ^
193| } // (lib.optionalAttrs (stdenv.hostPlatform != stdenv.buildPlatform && !dontAddHostSuffix && (attrs ? name || (attrs ? pname && attrs ? version)))) {
By default, once you enter x86_64 Rosetta 2, macOS will try to run
everything in x86_64. So an x86_64 Nix will still try to use x86_64
even when system = aarch64-darwin. To avoid this we can set
kern.curproc_arch_affinity sysctl. With kern.curproc_arch_affinity=0,
we ignore this preference.
This is based on how
https://opensource.apple.com/source/system_cmds/system_cmds-880.40.5/arch.tproj/arch.c.auto.html
works. Completely undocumented, but seems to work!
Note, you can verify this works with this impure Nix expression:
```
{
a = derivation {
name = "a";
system = "aarch64-darwin";
builder = "/bin/sh";
args = [ "-e" (builtins.toFile "builder" ''
[ "$(/usr/bin/arch)" = arm64 ]
[ "$(/usr/bin/arch -arch x86_64 /bin/sh -c /usr/bin/arch)" = i386 ]
[ "$(/usr/bin/arch -arch arm64 /bin/sh -c /usr/bin/arch)" = arm64 ]
/usr/bin/touch $out
'') ];
};
b = derivation {
name = "b";
system = "x86_64-darwin";
builder = "/bin/sh";
args = [ "-e" (builtins.toFile "builder" ''
[ "$(/usr/bin/arch)" = i386 ]
[ "$(/usr/bin/arch -arch x86_64 /bin/sh -c /usr/bin/arch)" = i386 ]
[ "$(/usr/bin/arch -arch arm64 /bin/sh -c /usr/bin/arch)" = arm64 ]
/usr/bin/touch $out
'') ];
};
}
```
We embrace virtual the rest of the way, and get rid of the
`assert(false)` 0-param constructors.
We also list config base classes first, so the constructor order is
always:
1. all the configs
2. all the stores
Each in the same order
