We want to be able to write down `foo.drv^bar.drv^baz`:
`foo.drv^bar.drv` is the dynamic derivation (since it is itself a
derivation output, `bar.drv` from `foo.drv`).
To that end, we create `Single{Derivation,BuiltPath}` types, that are
very similar except instead of having multiple outputs (in a set or
map), they have a single one. This is for everything to the left of the
rightmost `^`.
`NixStringContextElem` has an analogous change, and now can reuse
`SingleDerivedPath` at the top level. In fact, if we ever get rid of
`DrvDeep`, `NixStringContextElem` could be replaced with
`SingleDerivedPath` entirely!
Important note: some JSON formats have changed.
We already can *produce* dynamic derivations, but we can't refer to them
directly. Today, we can merely express building or example at the top
imperatively over time by building `foo.drv^bar.drv`, and then with a
second nix invocation doing `<result-from-first>^baz`, but this is not
declarative. The ethos of Nix of being able to write down the full plan
everything you want to do, and then execute than plan with a single
command, and for that we need the new inductive form of these types.
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
This enables nix to correctly report what will be fetched in the case
that everything is a cache hit.
Note however that if an intermediate build of something which is not
cached could still cause products to end up being substituted if the
intermediate build results in a CA path which is in the cache.
Fixes#8615.
Signed-off-by: Peter Waller <p@pwaller.net>
I haven't checked when this was exactly introduced, but on Nix 2.16 I
realized that the additional lines inserted when using `--precise` are
completely separated from the tree:
nix why-depends /nix/store/ccgr4faaxys39s091qridxg1947lggh4-evcxr-0.14.2 /nix/store/b7hvml0m3qmqraz1022fwvyyg6fc1vdy-gcc-12.2.0 --precise --extra-experimental-features nix-command
/nix/store/ccgr4faaxys39s091qridxg1947lggh4-evcxr-0.14.2
→ /nix/store/lcf37pgp3rgww67v9x2990hbfwx96c1w-gcc-wrapper-12.2.0
→ /nix/store/b7hvml0m3qmqraz1022fwvyyg6fc1vdy-gcc-12.2.0
└───bin/evcxr: …':'}.PATH=${PATH/':''/nix/store/lcf37pgp3rgww67v9x2990hbfwx96c1w-gcc-wrapper-12.2.0/bin'':'/':'}…
└───bin/cpp: …k disable=SC2193.[[ "/nix/store/b7hvml0m3qmqraz1022fwvyyg6fc1vdy-gcc-12.2.0/bin/cpp" = *++ ]] &&…
This is apparently because `std::cout` is buffered and flushed in the
end whereas the rest of the output isn't. The fix is rather simple, just
use `logger->cout` as it's already the case for the rest of the code.
This way we also don't need to insert additional newlines in the `hits`
map since that's something the logger takes care of.
Also added a small test to make sure that the layout of this is somehow
tested to reduce the risk of further regressions here.
Special-casing the file name is rather ugly, so we shouldn't do
that. So now any {file,http,https} URL is handled by
TarballInputScheme, except for non-flake inputs (i.e. inputs that have
the attribute `flake = false`).
Over the last year or so I've run into several use cases where I need to
parse and/or serialize URLs for use by `builtins.fetchTree` or
`builtins.getFlake`, largely in order to produce _lockfile-like_ files
for lang2nix frameworks or tools which use `nix` internally to drive
builds.
I've gone through the painstaking process of emulating
`nix::FlakeRef::fromAttrs` and `nix::parseFlakeRef` several times with
mixed success; but these are difficult to create and even harder to
maintain if I hope to stay aligned with changes to the real
parser/serializer.
I understand why adding new `builtins` isn't something we want to do
flagrantly. I'm recommending this addition simply because I keep
encountering use cases where I need to parse/serialize these URIs in
`nix` expressions, and I want a reliable solution.
Co-authored-by: Eelco Dolstra <edolstra@gmail.com>
Co-authored-by: John Ericson <git@JohnEricson.me>
Grouping our tests should make it easier to understand the intent than
one long poorly-arranged list. It also is convenient for running just
the tests for a specific component when working on that component.
We need at least one test group so this isn't dead code; I decided to
collect the tests for the `ca-derivations` and `dynamic-derivations`
experimental features in groups. Do
```bash
make ca.test-group -jN
```
and
```bash
make dyn-drv.test-group -jN
```
to try running just them.
I originally did this as part of #8397 for being able to just the local
overlay store alone. I am PRing it separately now so we can separate
general infra from new features.
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
We were bedeviled by sandboxing issues when working on the layered
store. The problem ended up being that when we have nested nix builds,
and the inner store is inside the build dir (e.g. store is
`/build/nix-test/$name/store`, build dir is `/build`) bind mounts
clobber each other and store paths cannot be found.
After thoroughly cleaning up `local-derivation-goal.cc`, we might be
able to make that work. But that is a lot of work. For now, we just fail
earlier with a proper error message.
Finally, test this: nested sandboxing without the problematic store dir
should work, and with should fail with the expected error message.
Co-authored-by: Dylan Green <67574902+cidkidnix@users.noreply.github.com>
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
When we pipe to `>(...)` like that, we unfortunately don't wait for the
process to finish. Better to just substitute the file.
Also, use the "unified" diff output that people (including myself) are
more familiar with, thanks to Git.
* Lang now verifies errors and parse output
* Some new miscellaneous tests
* Easy way to update the tests
* Document workflow in manual
* Use `!` not `~` as separater char for sed
It is confusing to use `~` when we are talking about paths and home
directories!
* Test test suite itself (`test/lang-test/infra.sh`)
Additionally, run shellcheck on `tests/lang.sh` to help ensure it is
correct, now that is is more complex.
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
When explicitly requested by the caller, as suggested in the meeting
(https://github.com/NixOS/nix/pull/8090#issuecomment-1531139324)
> @edolstra: { toPath } vs { fromPath } is too implicit
I've opted for the `inputAddressed = true` requirement, because it
we did not agree on renaming the path attributes.
> @roberth: more explicit
> @edolstra: except for the direction; not immediately clear in which direction the rewriting happens
This is in fact the most explicit syntax and a bit redundant, which is
good, because that redundancy lets us deliver an error message that
reminds expression authors that CA provides a better experience to
their users.
* nix flake check: improve error message if overlay is not a lambda
Suppose you have an overlay like this
{
inputs = { /* ... */ };
outputs = { flake-utils, ... }: flake-utils.lib.eachDefaultSystem
(system: {
overlays.default = final: prev: {
};
});
}
then `nix flake check` (correctly) fails because `overlays` are supposed
to have the structure `overlays.<name> = final: prev: exp`. However, the
error-message is a little bit counter-intuitive:
error: overlay does not take an argument named 'final'
While one might guess where the error actually comes from because the
trace above says `… while checking the overlay 'overlays.x86_64-linux'`
this is still pretty confusing because it complains about an argument
not being named `final` even though that's evidently the case.
With this change, the error-message actually makes it clear what's
wrong:
[ma27@carsten:~/Projects/nix/tmp]$ nix flake check --extra-experimental-features 'nix-command flakes' path:$(pwd)
error:
… while checking flake output 'overlays'
at /nix/store/clgblnxx003hyrq8qkz5ab6kgqkck6qc-source/flake.nix:4:5:
3| outputs = { ... }: {
4| overlays.x86_64-linux.snens = final: prev: {
| ^
5| kek = throw "snens";
… while checking the overlay 'overlays.x86_64-linux'
at /nix/store/clgblnxx003hyrq8qkz5ab6kgqkck6qc-source/flake.nix:4:5:
3| outputs = { ... }: {
4| overlays.x86_64-linux.snens = final: prev: {
| ^
5| kek = throw "snens";
error: overlay is not a lambda, but a set instead
