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.
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
The PR #4240 changed messag of the error that was thrown when an auto-called
function was missing an argument.
However this change also changed the type of the error, from `EvalError`
to a new `MissingArgumentError`. This broke hydra which was relying on
an `EvalError` being thrown.
Make `MissingArgumentError` a subclass of `EvalError` to un-break hydra.
When performing distributed builds of machine learning packages, it
would be nice if builders without the required SIMD instructions can
be excluded as build nodes.
Since x86_64 has accumulated a large number of different instruction
set extensions, listing all possible extensions would be unwieldy.
AMD, Intel, Red Hat, and SUSE have recently defined four different
microarchitecture levels that are now part of the x86-64 psABI
supplement and will be used in glibc 2.33:
https://gitlab.com/x86-psABIs/x86-64-ABIhttps://lwn.net/Articles/844831/
This change uses libcpuid to detect CPU features and then uses them to
add the supported x86_64 levels to the additional system types. For
example on a Ryzen 3700X:
$ ~/aps/bin/nix -vv --version | grep "Additional system"
Additional system types: i686-linux, x86_64-v1-linux, x86_64-v2-linux, x86_64-v3-linux
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
Change the `nix-build` logic for linking/printing the output paths to allow for
some outputs to be missing. This might happen when the toplevel
derivation didn't have to be built, either because all the required
outputs were already there, or because they have all been substituted.
I tested a trivial program that called kill(-1, SIGKILL), which was
run as the only process for an unpriveleged user, on Linux and
FreeBSD. On Linux, kill reported success, while on FreeBSD it failed
with EPERM.
POSIX says:
> If pid is -1, sig shall be sent to all processes (excluding an
> unspecified set of system processes) for which the process has
> permission to send that signal.
and
> The kill() function is successful if the process has permission to
> send sig to any of the processes specified by pid. If kill() fails,
> no signal shall be sent.
and
> [EPERM]
> The process does not have permission to send the signal to any
> receiving process.
My reading of this is that kill(-1, ...) may fail with EPERM when
there are no other processes to kill (since the current process is
ignored). Since kill(-1, ...) only attempts to kill processes the
user has permission to kill, it can't mean that we tried to do
something we didn't have permission to kill, so it should be fine to
interpret EPERM the same as success here for any POSIX-compliant
system.
This fixes an issue that Mic92 encountered[1] when he tried to review a
Nixpkgs PR on FreeBSD.
[1]: https://github.com/NixOS/nixpkgs/pull/81459#issuecomment-606073668
We upgrade to lowdown 0.8.0 [1] which contains a fix/improvement to a
behavior mentioned in this issue thread [2] where a big part of
lowdown's API would just call exit(1) on allocation errors since that
is a satisfying behavior for the lowdown binary.
Now lowdown_term_rndr returns 0 if an allocation error occurred which we
check for in libcmd/markdown.cc.
Also the extern "C" { } wrapper around lowdown.h has been removed as it
is not necessary.
[1]: 6ca7c855a0/versions.xml (L987-L1006)
[2]: https://github.com/kristapsdz/lowdown/issues/45#issuecomment-756681153
In addition to being some ugly template trickery, it was also totally
useless as it was used in only one place where I could replace it by
just a few extra characters
This makes nix search always go through the first level of an
attribute set, even if it's not a top level attribute. For instance,
you can now list all GHC compilers with:
$ nix search nixpkgs#haskell.compiler
...
This is similar to how nix-env works when you pass in -A.
This fixes an issue where derivations with a primary output that is
not "out" would fail with:
$ nix profile install nixpkgs#sqlite
error: opening directory '/nix/store/2a2ydlgyydly5czcc8lg12n6qqkfz863-sqlite-3.34.1-bin': No such file or directory
This happens because while derivations produce every output when
built, you might not have them if you didn't build the derivation
yourself (for instance, the store path was fetch from a binary cache).
This uses outputName provided from DerivationInfo which appears to
match the first output of the derivation.
Where a `RealisedPath` is a store path with its history, meaning either
an opaque path for stuff that has been directly added to the store, or a
`Realisation` for stuff that has been built by a derivation
This is a low-level refactoring that doesn't bring anything by itself
(except a few dozen extra lines of code :/ ), but raising the
abstraction level a bit is important on a number of levels:
- Commands like `nix build` have to query for the realisations after the
build is finished which is fragile (see
27905f12e4a7207450abe37c9ed78e31603b67e1 for example). Having them
oprate directly at the realisation level would avoid that
- Others like `nix copy` currently operate directly on (built) store
paths, but need a bit more information as they will need to register
the realisations on the remote side
Example:
error: builder for '/nix/store/9ysqfidhipyzfiy54mh77iqn29j6cpsb-failing.drv' failed with exit code 1;
last 1 log lines:
> FAIL
For full logs, run 'nix log /nix/store/9ysqfidhipyzfiy54mh77iqn29j6cpsb-failing.drv'.
… while importing '/nix/store/pfp4a4bjh642ylxyipncqs03z6kkgfvy-failing'
at /nix/store/25wgzr2qrqqiqfbdb1chpiry221cjglc-source/flake.nix:58:15:
57|
58| ifd = import self.hydraJobs.broken;
| ^
59|
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
Don't only show the name of the output, but also the derivation to which
this output belongs (as otherwise it's very hard to track back what went
wrong)
It's now
at /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix:7:7:
instead of
at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix
The new format is more standard and clickable.
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)))) {
This change is to simplify [Trustix](https://github.com/tweag/trustix) indexing and makes it possible to reconstruct this URL regardless of the compression used.
In particular this means that 7c2e9ca597/contrib/nix/nar/nar.go (L61-L71) can be removed and only the bits that are required to establish trust needs to be published in the Trustix build logs.
With the `ca-derivation` experimental features, non-ca derivations used
to have their output paths returned as unknown as long as they weren't
built (because of a mistake in the code that systematically erased the
previous value)
Thanks @regnat and @edolstra for catching this and comming up with the
solution.
They way I had generalized those is wrong, because local settings for
non-local stores is confusing default. And due to the nature of C++
inheritance, fixing the defaults is more annoying than it should be.
Additionally, I thought we might just drop the check in the substitution
logic since `Store::addToStore` is now streaming, but @regnat rightfully
pointed out that as it downloads dependencies first, that would still be
too late, and also waste effort on possibly unneeded/unwanted
dependencies.
The simple and correct thing to do is just make a store method for the
boolean logic, keeping all the setting and key stuff the way it was
before. That new method is both used by `LocalStore::addToStore` and the
substitution goal check. Perhaps we might eventually make it fancier,
e.g. sending the ValidPathInfo to remote stores for them to validate,
but this is good enough for now.
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
'') ];
};
}
```
This resolves#3810 by changing the behavior of `max-jobs = 0`, so
that specifying the option also avoids local building of derivations
with the attribute `preferLocalBuild = true`.
It appears as through the fetch attribute, which
is simply a variant with 3 elements, implicitly
converts boolean arguments to integers. One must
use Explicit<bool> to correctly populate it with
a boolean. This was missing from the implementation,
and resulted in clearly boolean JSON fields being
treated as numbers.
libc++10 seems to be stricter on what it allows in variant conversion.
I'm not sure what the rules are here, but this is the minimal change
needed to get through the compilation errors.
Sometimes it's necessary to fetch a git repository at a revision and
it's unknown which ref contains the revision in question. An example
would be a Cargo.lock which only provides the URL and the revision when
using a git repository as build input.
However it's considered a bad practice to perform a full checkout of a
repository since this may take a lot of time and can eat up a lot of
disk space. This patch makes a full checkout explicit by adding an
`allRefs` argument to `builtins.fetchGit` which fetches all refs if
explicitly set to true.
Closes#2409
A common pitfall when using e.g. `builtins.fetchGit` is the `fatal: not
a tree object`-error when trying to fetch a revision of a git-repository
that isn't on the `master` branch and no `ref` is specified.
In order to make clear what's the problem, I added a simple check
whether the revision in question exists and if it doesn't a more
meaningful error-message is displayed:
```
nix-repl> builtins.fetchGit { url = "https://github.com/owner/myrepo"; rev = "<commit not on master>"; }
moderror: --- Error -------------------------------------------------------------------- nix
Cannot find Git revision 'bf1cc5c648e6aed7360448a3745bb2fe4fbbf0e9' in ref 'master' of repository 'https://gitlab.com/Ma27/nvim.nix'! Please make sure that the rev exists on the ref you've specified or add allRefs = true; to fetchGit.
```
Closes#2431
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
Move clearValue inside Value
mkInt instead of setInt
mkBool instead of setBool
mkString instead of setString
mkPath instead of setPath
mkNull instead of setNull
mkAttrs instead of setAttrs
mkList instead of setList*
mkThunk instead of setThunk
mkApp instead of setApp
mkLambda instead of setLambda
mkBlackhole instead of setBlackhole
mkPrimOp instead of setPrimOp
mkPrimOpApp instead of setPrimOpApp
mkExternal instead of setExternal
mkFloat instead of setFloat
Add note that the static mk* function should be removed eventually
PRs #4370 and #4348 had a bad interaction in that the second broke the fist
one in a not trivial way.
The issue was that since #4348 the logic for detecting whether a
derivation output is already built requires some logic that was specific
to the `LocalStore`.
It happens though that most of this logic could be upstreamed to any `Store`,
which is what this commit does.
This ignore was here because `queryPartialDrvOutputMap` was used both
1. as a cache to avoid having to re-read the derivation (when gc-ing for
example), and
2. as the source of truth for ca realisations
The use-case 2. required it to be able to work even when the derivation
wasn't there anymore (see https://github.com/NixOS/nix/issues/4138).
However, this use-case is now handled by `queryRealisation`, meaning
that we can safely error out if the derivation isn't there anymore
`buildPaths` can be called even for stores where it's not defined in case it's
bound to be a no-op.
The “no-op detection” mechanism was only detecting the case wher `buildPaths`
was called on a set of (non-drv) paths that were already present on the store.
This commit extends this mechanism to also detect the case where `buildPaths`
is called on a set of derivation outputs which are already built on the store.
This only works with the ca-derivations flag. It could be possible to
extend this to also work without it, but it would add quite a bit of
complexity, and it's not used without it anyways.
Extend `FSAccessor::readFile` to allow not checking that the path is a
valid one, and rewrite `readInvalidDerivation` using this extended
`readFile`.
Several places in the code use `readInvalidDerivation`, either because
they need to read a derivation that has been written in the store but
not registered yet, or more generally to prevent a deadlock because
`readDerivation` tries to lock the state, so can't be called from a
place where the lock is already held.
However, `readInvalidDerivation` implicitely assumes that the store is a
`LocalFSStore`, which isn't always the case.
The concrete motivation for this is that it's required for `nix copy
--from someBinaryCache` to work, which is tremendously useful for the
tests.
Because of a too eager refactoring, `addTextToStore` used to throw an
error because the input wasn't a valid nar.
Partially revert that refactoring to wrap the text into a proper nar
(using `dumpString`) to make this method work again
Rather than storing the derivation outputs as `drvPath!outputName` internally,
store them as `drvHashModulo!outputName` (or `outputHash!outputName` for
fixed-output derivations).
This makes the storage slightly more opaque, but enables an earlier
cutoff in cases where a fixed-output dependency changes (but keeps the
same output hash) − same as what we already do for input-addressed
derivations.
Add a new table for tracking the derivation output mappings.
We used to hijack the `DerivationOutputs` table for that, but (despite its
name), it isn't a really good fit:
- Its entries depend on the drv being a valid path, making it play badly with
garbage collection and preventing us to copy a drv output without copying
the whole drv closure too;
- It dosen't guaranty that the output path exists;
By using a different table, we can experiment with a different schema better
suited for tracking the output mappings of CA derivations.
(incidentally, this also fixes#4138)
For each known realisation, store:
- its output
- its output path
This comes with a set of needed changes:
- New `realisations` module declaring the types needed for describing
these mappings
- New `Store::registerDrvOutput` method registering all the needed informations
about a derivation output (also replaces `LocalStore::linkDeriverToPath`)
- new `Store::queryRealisation` method to retrieve the informations for a
derivations
This introcudes some redundancy on the remote-store side between
`wopQueryDerivationOutputMap` and `wopQueryRealisation`.
However we might need to keep both (regardless of backwards compat)
because we sometimes need to get some infos for all the outputs of a
derivation (where `wopQueryDerivationOutputMap` is handy), but all the
stores can't implement it − because listing all the outputs of a
derivation isn't really possible for binary caches where the server
doesn't allow to list a directory.
In `nixStable` (2.3.7 to be precise) it's possible to connect to stores
using an IPv6 address:
nix ping-store --store ssh://root@2001:db8::1
This is also useful for `nixops(1)` where you could specify an IPv6
address in `deployment.targetHost`.
However, this behavior is broken on `nixUnstable` and fails with the
following error:
$ nix store ping --store ssh://root@2001:db8::1
don't know how to open Nix store 'ssh://root@2001:db8::1'
This happened because `openStore` from `libstore` uses the `parseURL`
function from `libfetchers` which expects a valid URL as defined in
RFC2732. However, this is unsupported by `ssh(1)`:
$ nix store ping --store 'ssh://root@[2001:db8::1]'
cannot connect to 'root@[2001:db8::1]'
This patch now allows both ways of specifying a store (`root@2001:db8::1`) and
also `root@[2001:db8::1]` since the latter one is useful to pass query
parameters to the remote store.
In order to achieve this, the following changes were made:
* The URL regex from `url-parts.hh` now allows an IPv6 address in the
form `2001:db8::1` and also `[2001:db8::1]`.
* In `libstore`, a new function named `extractConnStr` ensures that a
proper URL is passed to e.g. `ssh(1)`:
* If a URL looks like either `[2001:db8::1]` or `root@[2001:db8::1]`,
the brackets will be removed using a regex. No additional validation
is done here as only strings parsed by `parseURL` are expected.
* In any other case, the string will be left untouched.
* The rules above only apply for `LegacySSHStore` and `SSHStore` (a.k.a
`ssh://` and `ssh-ng://`).
Unresolved questions:
* I'm not really sure whether we want to allow both variants of IPv6
addresses in the URL parser. However it should be noted that both seem
to be possible according to RFC2732:
> This document incudes an update to the generic syntax for Uniform
> Resource Identifiers defined in RFC 2396 [URL]. It defines a syntax
> for IPv6 addresses and allows the use of "[" and "]" within a URI
> explicitly for this reserved purpose.
* Currently, it's not supported to specify a port number behind the
hostname, however it seems as this is not really supported by the URL
parser. Hence, this is probably out of scope here.
The `DerivationGoal` has a variable storing the “final” derivation
output paths that is used (amongst other things) to fill the environment
for the post build hook. However this variable wasn't set when the
build-hook is used, causing a crash when both hooks are used together.
Fix this by setting this variable (from the informations in the db) after a run
of the post build hook.
This reverts commit 1b1e076033.
Using `queryPartialDerivationOutputMap` assumes that the derivation
exists locally which isn't the case for remote builders.
Since 0744f7f, it is now useful to have cache.nixos.org in substituers
even if /nix/store is not the Nix Store Dir. This can always be
overridden via configuration, though.
