`eval-system` option overrides just the value of `builtins.currentSystem`.
This is more useful than overriding `system` since you can build these
derivations on remote builders which can work on the given system.
Co-authored-by: John Ericson <John.Ericson@Obsidian.Systems>
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
I wrote the `configure.ac` wrong, and so we just got no builds
supporting ACLs.
Also, it needs to be more precise because Darwin puts other stuff in
that same header, evidently.
I don't love the way this code looks. There are two larger problems:
- eval, build/scratch, destination stores (#5025) should have different
types to reflect the fact that they are used for different purposes
and those purposes correspond to different operations. It should be
impossible to "use the wrong store" in my cases.
- Since drvs can end up in both the eval and build/scratch store, we
should have some sort of union/layered store (not on the file sytem
level, just conceptual level) that allows accessing both. This would
get rid of the ugly "check both" boilerplate in this PR.
Still, it might be better to land this now / soon after minimal cleanup,
so we have a concrete idea of what problem better abstractions are
supposed to solve.
Below the comment added by this commit is a much longer comment
followed by a trust check, both of which have confused me on at
least two occasions. I figured it out once, forgot it, then had to
ask @Ericson2314 to explain it, at which point I understood it
again. I think this might confuse other people too, or maybe I will
just forget it a third time. So let's add a comment.
Farther down in the function is the following check:
```
if (!(drvType.isCA() || trusted))
throw Error("you are not privileged to build input-addressed derivations");
```
This seems really strange at first. A key property of Nix is that
you can compute the outpath of a derivation using the derivation
(and its references-closure) without trusting anybody!
The missing insight is that at this point in the code the builder
doesn't necessarily have the references-closure of the derivation
being built, and therefore needs to trust that the derivation's
outPath is honest. It's incredibly easy to overlook this, because
the only difference between these two cases is which of these
identically-named functions we used:
- `readDerivation(Source,Store)`
- `Store::readDerivation()`
These functions have different trust models (except in the special
case where the first function is used on the local store). We
should call the reader's attention to this fact.
Co-authored-by: Cole Helbling <cole.e.helbling@outlook.com>
In https://github.com/NixOS/nix/pull/6134#issuecomment-1079199888,
@thuffschmitt proposed exposing `LegacySSHStore` in Nix for
deduplication with Hydra, at least temporarily. I think that is a good
idea.
Note that the diff will look bad unless one ignores whitespace! Also try
this locally:
```shell-session
git diff --ignore-all-space HEAD^:src/libstore/legacy-ssh-store.cc HEAD:src/libstore/legacy-ssh-store.cc
git diff --ignore-all-space HEAD^:src/libstore/legacy-ssh-store.cc HEAD:src/libstore/legacy-ssh-store.hh
```
This is needed for building CA deriations with a src store / dest store
split. In particular it is needed for Hydra.
https://github.com/NixOS/hydra/issues/838 currently puts realizations,
and thus build outputs, in the local store, but it should not.
In the process, partially undo e89b5bd0bf
in that the ancient < 2.4 version is now supported again by the
serializer again. `LegacySSHStore`, instead of also asserting that the
version is at least 4, just checks that `narHash` is set.
This allows us to better test the serializer in isolation for both
versions (< 4 and >= 4).
Today, with the tests inside a `tests` intermingled with the
corresponding library's source code, we have a few problems:
- We have to be careful that wildcards don't end up with tests being
built as part of Nix proper, or test headers being installed as part
of Nix proper.
- Tests in libraries but not executables is not right:
- It means each executable runs the previous unit tests again, because
it needs the libraries.
- It doesn't work right on Windows, which doesn't want you to load a
DLL just for the side global variable . It could be made to work
with the dlopen equivalent, but that's gross!
This reorg solves these problems.
There is a remaining problem which is that sibbling headers (like
`hash.hh` the test header vs `hash.hh` the main `libnixutil` header) end
up shadowing each other. This PR doesn't solve that. That is left as
future work for a future PR.
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
This makes for more useful manual table of contents, that displays the
information at a glance.
The `nix help-stores` command is kept as-is, even though it will show up
in the manual with the same information as these pages due to the way it
is written as a "`--help`-style" command. Deciding what to do with that
command is left for a later PR.
This change also lists all store types at the top of the respective overview page.
Co-authored-by: John Ericson <John.Ericson@Obsidian.Systems
The problem was that f880469173 forgot
that the `#include <sys/xattr.h>` was guarded by an `#ifdef __linux__`.
However, the build failure was only on FreeBSD --- turns out other
platforms have this header too!
The fix therefore uses a new configure check so we properly clear ACLs
on more platforms.
`installcheck` doesn't yet work, but the rest of the build can now
happen mostly inside a separate build directory.
Progress on #9342
Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io>
It is not inherently tied to `LocalStore`, it could probably even go in
`libnixutil`. Functions not attached to `LocalStore` should not be
declared in `local-store.hh`.
I am moving it to facilitate experimenting for #9344. If
canonicalisation should be done client-side in client-side builds, there
wouldn't be a `LocalStore` at all so having to include that header to
get this freestanding function is cumbersome and wrong.
Perhaps canonicalisation should still be done server-side for security
reasons --- I don't mean to make that judgement call now --- but even if
so, this freestanding function still isn't connected to `LocalStore` so
while less urgent it is still better to move out of this header.
This avoids repeated copying of the same source tree between Nix
invocations. It requires the accessor to have a "fingerprint" (e.g. a
Git revision) that uniquely determines its contents.
Closes#9343
See that issue for motivation.
Installing these is disabled by default, but we enable it (and the
additional output we want isntall these too so as not to clutter the
existing ones) to use in cross builds and dev shells.
