This opens the door to derivations that *directly* specify their
options, rather than "stealing" environment variables to do so.
The A-Term derivation format used on disk didn't change --- we cannot do
that for existing derivations, so those derivations will continue to not
support separate options. But having a more flexible JSON format opens
the door to extending the on-disk format in others, like directly using
JSON, using CBOR, etc.
Co-authored-by: HaeNoe <git@haenoe.party>
Co-authored-by: Jonathan Gibbons <jonored@gmail.com>
This is an example of "Parse, don't validate" principle [1].
Before, we had a number of `StringSet`s in `DerivationOptions` that
were not *actually* allowed to be arbitrary sets of strings. Instead,
each set member had to be one of:
- a store path
- a CA "downstream placeholder"
- an output name
Only later, in the code that checks outputs, would these strings be
further parsed to match these cases. (Actually, only 2 by that point,
because the placeholders must be rewritten away by then.)
Now, we fully parse everything up front, and have an "honest" data type
that reflects these invariants:
- store paths are parsed, stored as (opaque) deriving paths
- CA "downstream placeholders" are rewritten to the output deriving
paths they denote
- output names are the only arbitrary strings left
Since the first two cases both become deriving paths, that leaves us
with a `std::variant<SingleDerivedPath, String>` data type, which we use
in our sets instead.
Getting rid of placeholders is especially nice because we are replacing
them with something much more internally-structured / transparent.
[1]: https://lexi-lambda.github.io/blog/2019/11/05/parse-don-t-validate/
Co-authored-by: Sergei Zimmerman <sergei@zimmerman.foo>
`allowedReferences` and friends can, in addition to supporting store
paths (and placeholders, but because those will be rewritten to store
paths), they also support to refering to other outputs in the derivation
by name.
We update the tests in order to cover for that.
(While we are at it, also introduce some scratch variables for paths and
placeholders to make the C++ literalsf for this test more concise.)
The old string format is a holdover from the pre JSON days. It is not
friendly to users who need to get the information out of it.
Also introduce the sort of versioning we have for derivation for this
format too.
- Use canonical content address JSON format for floating content
addressed derivation outputs
This keeps it more consistent.
- Reorganize inputs into nested structure (`inputs.srcs` and
`inputs.drvs`)
This will allow for an easier to use, but less compact, alternative
where `srcs` is just a list of derived paths.
It also allows for other experiments for derivations with a different
input structure, as I suspect will be needed for secure build traces.
Have one to that instead of one to `Derivation`. `DerivationBuilder`
doesn't need `inputDrvs`, so `BasicDerivation` suffices.
(In fact, it doesn't need `inputSrcs` either, but we don't yet hve a
type to exclude that.)
We were calling git with `--quiet` in order not to mess up Nix's
progress bar. However, `runProgram()` already suspends the progress
bar (since git may be interactive) so that's no longer an issue. So we
can just run with `--progress` instead.
Fix#14480
This method is not well-defined for arbitrary stores, which do not have
a notion of a "real path" -- it is only well-defined for local file
systems stores, which do have exactly that notion, and so it is moved to
that sub-interface instead.
Some call-sites had to be fixed up for this, but in all cases the
changes are positive. Using `getFSSourceAccessor` allows for more other
stores to work properly. `nix-channel` was straight-up wrong in the case
of redirected local stores. And the building logic with remote building
and a non-local store is also fixed, properly gating some deletions on
store type.
Co-authored-by: Robert Hensing <robert@roberthensing.nl>
The assumption that no unknown paths can be returned is incorrect. It
can happen if a derivation has outputs that are substitutable, but
that have references that cannot be substituted (i.e. an incomplete
closure in the binary cache). This can easily happen with
magic-nix-cache.
Previously, only shared memory segments were cleaned up.
This could lead to leaked message queues and semaphore sets when builds use System V IPC, exhausting kernel IPC limits over time.
This commit extends the cleanup to all three System V IPC types:
1. Shared memory segments
2. Message queues
3. Semaphores
Additionally, we stop removing IPC objects during iteration, as it could corrupt the kernel's iterator state and cause some objects to be skipped. The new implementation uses a two-pass approach where we list first and then remove them in a separate pass.
The IPC IDs are now extracted during iteration using actual system calls (shmget, msgget, semget) rather than being looked up later, ensuring the objects exist when we capture their IDs.
In Linux, IPC objects are automatically cleaned up when the IPC namespace is destroyed.
On Darwin, since there are no IPC namespaces, the IPC objects may sometimes persist after the build user's processes are killed.
This patch modifies the cleanup logic to use sysctl calls to identify and remove left over shm segments associated with the build user.
Fixes: #12548
For repos with a lot of non-linearity in the commit graph (like
Nixpkgs), this speeds up getting the revcount a lot, e.g. `nix flake
metadata /path/to/nixpkgs?rev=9dc7035bbee85ffc740d893e02cb64460f11989f` went
from 9.1s to 3.7s.
