I think that it's not very helpful to get "cached failures" in a wrong
`flake.nix`. This can be very confusing when debugging a Nix expression.
See for instance NixOS/nixpkgs#118115.
In fact, the eval cache allows a forced reevaluation which is used for
e.g. `nix eval`.
This change makes sure that this is the case for `nix build` as well. So
rather than
λ ma27 [~/Projects/exp] → ../nix/outputs/out/bin/nix build -L --rebuild --experimental-features 'nix-command flakes'
error: cached failure of attribute 'defaultPackage.x86_64-linux'
the evaluation of already-evaluated (and failed) attributes looks like
this now:
λ ma27 [~/Projects/exp] → ../nix/outputs/out/bin/nix build -L --rebuild --experimental-features 'nix-command flakes'
error: attribute 'hell' missing
at /nix/store/mrnvi9ss8zn5wj6gpn4bcd68vbh42mfh-source/flake.nix:6:35:
5|
6| packages.x86_64-linux.hello = nixpkgs.legacyPackages.x86_64-linux.hell;
| ^
7|
(use '--show-trace' to show detailed location information)
When working on some more complex Nix code, there are sometimes rather
unhelpful or misleading error messages, especially if coerce-errors are
thrown.
This patch is a first steps towards improving that. I'm happy to file
more changes after that, but I'd like to gather some feedback first.
To summarize, this patch does the following things:
* Attrsets (a.k.a. `Bindings` in `libexpr`) now have a `Pos`. This is
helpful e.g. to identify which attribute-set in `listToAttrs` is
invalid.
* The `Value`-struct has a new method named `determinePos` which tries
to guess the position of a value and falls back to a default if that's
not possible.
This can be used to provide better messages if a coercion fails.
* The new `determinePos`-API is used by `builtins.concatMap` now. With
that change, Nix shows the exact position in the error where a wrong
value was returned by the lambda.
To make sure it's still obvious that `concatMap` is the problem,
another stack-frame was added.
* The changes described above can be added to every other `primop`, but
first I'd like to get some feedback about the overall approach.
* The position of the `name`-attribute appears in the trace.
* If e.g. `meta` has no `outPath`-attribute, a `cannot coerce set to
string` error will be thrown where `pos` points to `name =` which is
highly misleading.
If there were many top-level goals (which are not destroyed until the
very end), commands like
$ nix copy --to 'ssh://localhost?remote-store=/tmp/nix' \
/run/current-system --no-check-sigs --substitute-on-destination
could fail with "Too many open files". So now we do some explicit
cleanup from amDone(). It would be cleaner to separate goals from
their temporary internal state, but that would be a bigger refactor.
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).
These are by no means part of the notion of a store, but rather are
things that happen to use stores. (Or put another way, there's no way
we'd make them virtual methods any time soon.) It's better to move them
out of that too-big class then.
Also, this helps us remove StorePathWithOutputs from the Store interface
altogether next commit.
This fixes builtins.fetchGit { url = ...; ref = "HEAD"; }, that works in
stable nix (v2.3.10), but is broken in nix master:
$ ./result/bin/nix repl
Welcome to Nix version 2.4pre19700101_dd77f71. Type :? for help.
nix-repl> builtins.fetchGit { url = "https://github.com/NixOS/nix"; ref = "HEAD"; }
fetching Git repository 'https://github.com/NixOS/nix'fatal: couldn't find remote ref refs/heads/HEAD
error: program 'git' failed with exit code 128
The documentation for builtins.fetchGit says ref = "HEAD" is the
default, so it should also be supported to explicitly pass it.
I came across this issue because poetry2nix can use ref = "HEAD" in some
situations.
Fixes#4674.
A few versioning mistakes were corrected:
- In 27b5747ca7, Daemon protocol had some
version `>= 0xc` that should have been `>= 0x1c`, or `28` since the
other conditions used decimal.
- In a2b69660a9, legacy SSH gated new CAS
info on version 6, but version 5 in the server. It is now 6
everywhere.
Additionally, legacy ssh was sending over more metadata than the daemon
one was. The daemon now sends that data too.
CC @regnat
Co-authored-by: Cole Helbling <cole.e.helbling@outlook.com>
According to RFC4007[1], IPv6 addresses can have a so-called zone_id
separated from the actual address with `%` as delimiter. In contrast to
Nix 2.3, the version on `master` doesn't recognize it as such:
$ nix ping-store --store ssh://root@fe80::1%18 --experimental-features nix-command
warning: 'ping-store' is a deprecated alias for 'store ping'
error: --- Error ----------------------------------------------------------------- nix
don't know how to open Nix store 'ssh://root@fe80::1%18'
I modified the IPv6 match-regex accordingly to optionally detect this
part of the address. As we don't seem to do anything special with it, I
decided to leave it as part of the URL for now.
Fixes#4490
[1] https://tools.ietf.org/html/rfc4007
I guess the rationale behind the old name wath that
`pathInfoIsTrusted(info)` returns `true` iff we would need to `blindly`
trust the path (because it has no valid signature and `requireSigs` is
set), but I find it to be a really confusing footgun because it's quite
natural to give it the opposite meaning.
When starting a nix-shell with `-i` it was previously possible for it to
silently fail in the scenario where the specified interpreter didn't
exist. This happened due to the `exec` call masking the issue.
With this change we enable `execfail`, which causes the script using
`nix-shell` as interpreter to correctly exit with code 127.
Fixes: #4598
Basically, if a tarball URL is used as a flake input, and the URL leads
to a redirect, the final redirect destination would be recorded as the
locked URL.
This allows tarballs under https://nixos.org/channels to be used as
flake inputs. If we, as before, lock on to the original URL it would
break every time the channel updates.
Local git repositories are normally used directly instead of
cloning. This commit checks if a repo is bare and forces a
clone.
Co-authored-by: Théophane Hufschmitt <regnat@users.noreply.github.com>
What happened was that Nix was trying to unconditionally mount these
paths in fixed-output derivations, but since the outer derivation was
pure, those paths did not exist. The solution is to only mount those
paths when they exist.
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 is probably what most people expect it to do. Fixes#3781.
There is a new command 'nix flake lock' that has the old behaviour of
'nix flake update', i.e. it just adds missing lock file entries unless
overriden using --update-input.
This is already used by Hydra, and is very useful when materializing
a remote builder list from service discovery. This allows the service
discovery tool to only sync one file instead of two.
This is technically a breaking change, since attempting to set plugin
files after the first non-flag argument will now throw an error. This
is acceptable given the relative lack of stability in a plugin
interface and the need to tie the knot somewhere once plugins can
actually define new subcommands.
