This adds a second form to the `:log` command: it now can accept a
derivation path in addition to a derivation expression. As derivation
store paths start with `/nix/store`, this is not ambiguous.
Resolves: lix-project/lix#51
Change-Id: Iebc7b011537e7012fae8faed4024ea1b8fdc81c3
The original attempt at this introduced a regression; this commit
reverts the revert and fixes the regression.
This reverts commit 3e151d4d77.
Fix to the regression:
flakeref: fix handling of `?dir=` param for flakes in subdirs
As reported in #419[1], accessing a flake in a subdir of a Git
repository fails with the previous commit[2] applied with the error
error: unsupported Git input attribute 'dir'
The problem is that the `dir`-param is inserted into the parsed URL if a
flake is fetched from the subdir of a Git repository. However, for the
fetching part this isn't even needed. The fix is to just pass `subdir`
as second argument to `FlakeRef` (which needs a `basedir` that can be
empty) and leave the parsedURL as-is.
Added a regression test to make sure we don't run into this again.
[1] lix-project/lix#419
[2] e22172aaf6b6a366cecd3c025590e68fa2b91bcc,
originally 3e151d4d77
Change-Id: I2c72d5a32e406a7ca308e271730bd0af01c5d18b
What if you could find memory bugs in Lix without really trying very
hard? I've had variously scuffed patches to do this, but this is
blocked on boost coroutines removal at this point tbh.
Change-Id: Id762af076aa06ad51e77a6c17ed10275929ed578
If `:edit`ing a store path, don't reload repl afterwards
to avoid losing local variables: store is immutable,
so "editing" a store path is always just viewing it.
Resolves: lix-project/lix#341
Change-Id: I3747f75ce26e0595e953069c39ddc3ee80699718
(cherry picked from commit 8cd1d02f90eb9915e640c5d370d919fad9833c65)
nix flake show: Only print up to the first new line if it exists.
(cherry picked from commit 5281a44927bdb51bfe6e5de12262d815c98f6fe7)
add tests
(cherry picked from commit 74ae0fbdc70a5079a527fe143c4832d1357011f7)
Handle long strings, embedded new lines and empty descriptions
(cherry picked from commit 2ca7b3afdbbd983173a17fa0a822cf7623601367)
Account for total length of 80
(cherry picked from commit 1cc808c18cbaaf26aaae42bb1d7f7223f25dd364)
docs: add nix flake show description release note
fix: remove white space
nix flake show: trim length based on terminal size
test: account for terminal size
docs(flake-description): before and after commands; add myself to credits
Upstream-PR: https://github.com/NixOS/nix/pull/10980
Change-Id: Ie1c667dc816b3dd81e65a1f5395e57ea48ee0362
This removes a *whole load* of variables from scope and enforces thread
boundaries with the type system.
There is not much change of significance in here, so the things to watch
out for while reviewing it are primarily that the destructor ordering
may have changed inadvertently, I think.
Change-Id: I3cd87e6d5a08dfcf368637407251db22a8906316
When pretty-printing is enabled, previously an unforced thunk would trigger
indentation, even when it subsequently does not evaluate to a nested structure.
The resulting output looked inconsistent, and furthermore pretty-printing was
not idempotent (since pretty-printing the same value again, which is now fully
evaluated, will not trigger indentation).
When strict evaluation is enabled, force the item before inspecting its type,
so that it is properly known whether it contains a nested structure.
Furthermore, there is no need to cause indentation for unforced thunks, since
the very next operation will be printing them as `«thunk»`.
This is mostly a port of https://github.com/NixOS/nix/pull/11100 , but we only
force the item when it's going to be forced anyway due to strict
pretty-printing, and a new test was written since the REPL testing framework in
Lix is different.
Co-Authored-By: Robert Hensing <robert@roberthensing.nl>
Change-Id: Ib7560fe531d09e05ca6b2037a523fe21a26d9d58
Previous test implementation assumed that grep supports newlines
in patterns. It doesn't, so tests spuriously passed, even though
some tests outputs were broken.
This patches output (and expected output) before grepping,
so there're no newlines in pattern.
Change-Id: Ie6561f9f2e18b83d976f162269d20136e2595141
This also bans various sneaking of negative numbers from the language
into unsuspecting builtins as was exposed while auditing the
consequences of changing the Nix language integer type to a newtype.
It's unlikely that this change comprehensively ensures correctness when
passing integers out of the Nix language and we should probably add a
checked-narrowing function or something similar, but that's out of scope
for the immediate change.
During the development of this I found a few fun facts about the
language:
- You could overflow integers by converting from unsigned JSON values.
- You could overflow unsigned integers by converting negative numbers
into them when going into Nix config, into fetchTree, and into flake
inputs.
The flake inputs and Nix config cannot actually be tested properly
since they both ban thunks, however, we put in checks anyway because
it's possible these could somehow be used to do such shenanigans some
other way.
Note that Lix has banned Nix language integer overflows since the very
first public beta, but threw a SIGILL about them because we run with
-fsanitize=signed-overflow -fsanitize-undefined-trap-on-error in
production builds. Since the Nix language uses signed integers, overflow
was simply undefined behaviour, and since we defined that to trap, it
did.
Trapping on it was a bad UX, but we didn't even entirely notice
that we had done this at all until it was reported as a bug a couple of
months later (which is, to be fair, that flag working as intended), and
it's got enough production time that, aside from code that is IMHO buggy
(and which is, in any case, not in nixpkgs) such as
lix-project/lix#445, we don't think
anyone doing anything reasonable actually depends on wrapping overflow.
Even for weird use cases such as doing funny bit crimes, it doesn't make
sense IMO to have wrapping behaviour, since two's complement arithmetic
overflow behaviour is so *aggressively* not what you want for *any* kind
of mathematics/algorithms. The Nix language exists for package
management, a domain where bit crimes are already only dubiously in
scope to begin with, and it makes a lot more sense for that domain for
the integers to never lose precision, either by throwing errors if they
would, or by being arbitrary-precision.
This change will be ported to CppNix as well, to maintain language
consistency.
Fixes: lix-project/lix#423
Change-Id: I51f253840c4af2ea5422b8a420aa5fafbf8fae75
`nix-collect-garbage --dry-run` previously elided the entire garbage
collection check, meaning that it would just exit the script without
printing anything.
This change makes the dry run flag instead set the GC action to
`gcReturnDead` rather than `gcDeleteDead`, and then continue with the
script. So if you set `--dry-run`, it will print the paths it *would*
have garbage collected, but not actually delete them.
I filed a bug for this: lix-project/lix#432 but then realised I could give fixing it a go myself.
Change-Id: I062dbf1a80bbab192b5fd0b3a453a0b555ad16f2
Turns errors like this:
let
throwMsg = a: throw (a + " invalid bar");
in throwMsg "bullshit"
error:
… from call site
at «string»:3:4:
2| throwMsg = a: throw (a + " invalid bar");
3| in throwMsg "bullshit"
| ^
… while calling 'throwMsg'
at «string»:2:14:
1| let
2| throwMsg = a: throw (a + " invalid bar");
| ^
3| in throwMsg "bullshit"
… while calling the 'throw' builtin
at «string»:2:17:
1| let
2| throwMsg = a: throw (a + " invalid bar");
| ^
3| in throwMsg "bullshit"
error: bullshit invalid bar
into errors like this:
let
throwMsg = a: throw (a + " invalid bar");
in throwMsg "bullshit"
error:
… from call site
at «string»:3:4:
2| throwMsg = a: throw (a + " invalid bar");
3| in throwMsg "bullshit"
| ^
… while calling 'throwMsg'
at «string»:2:14:
1| let
2| throwMsg = a: throw (a + " invalid bar");
| ^
3| in throwMsg "bullshit"
… caused by explicit throw
at «string»:2:17:
1| let
2| throwMsg = a: throw (a + " invalid bar");
| ^
3| in throwMsg "bullshit"
error: bullshit invalid bar
Change-Id: I593688928ece20f97999d1bf03b2b46d9ac338cb
Turns errors like:
let
errpkg = throw "invalid foobar";
in errpkg.meta
error:
… while calling the 'throw' builtin
at «string»:2:12:
1| let
2| errpkg = throw "invalid foobar";
| ^
3| in errpkg.meta
error: invalid foobar
into errors like:
let
errpkg = throw "invalid foobar";
in errpkg.meta
error:
… while evaluating 'errpkg' to select 'meta' on it
at «string»:3:4:
2| errpkg = throw "invalid foobar";
3| in errpkg.meta
| ^
… while calling the 'throw' builtin
at «string»:2:12:
1| let
2| errpkg = throw "invalid foobar";
| ^
3| in errpkg.meta
error: invalid foobar
For the low price of one try/catch, you too can have the incorrect line
of code actually show up in the trace!
Change-Id: If8d6200ec1567706669d405c34adcd7e2d2cd29d
The `allow-flake-configuration` option allows the user to control whether to
accept configuration options supplied by flakes. Unfortunately, setting this
to false really meant "ask each time" (with an option to remember the choice
for each specific option encountered). Let no mean no, and introduce (and
default to) a separate value for the "ask each time" behaviour.
Co-Authored-By: Jade Lovelace <lix@jade.fyi>
Change-Id: I7ccd67a95bfc92cffc1ebdc972d243f5191cc1b4
We previously allowed you to map any flake URL to any other flake URL,
including shorthand flakerefs, indirect flake URLs like `flake:nixpkgs`,
direct flake URLs like `github:NixOS/nixpkgs`, or local paths.
But flake registry entries mapping from direct flake URLs often come
from swapping the 'from' and 'to' arguments by accident, and even when
created intentionally, they may not actually work correctly.
This patch rejects those URLs (and fully-qualified flake: URLs), making
it harder to swap the arguments by accident.
Fixes#181.
Change-Id: I24713643a534166c052719b8770a4edfcfdb8cf3
This is a shameless layering violation in favour of UX. It falls back
trivially to "unknown", so it's purely a UX feature.
Diagnostic sample:
```
error: hash mismatch in fixed-output derivation '/nix/store/sjfw324j4533lwnpmr5z4icpb85r63ai-x1.drv':
likely URL: https://meow.puppy.forge/puppy.tar.gz
specified: sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
got: sha256-a1Qvp3FOOkWpL9kFHgugU1ok5UtRPSu+NwCZKbbaEro=
```
Change-Id: I873eedcf7984ab23f57a6754be00232b5cb5b02c
this gives about 20% performance improvements on pure parsing. obviously
it will be less on full eval, but depending on how much parsing is to be
done (e.g. including hackage-packages.nix or not) it's more like 4%-10%.
this has been tested (with thousands of core hours of fuzzing) to ensure
that the ASTs produced by the new parser are exactly the same as the old
one would have produced. error messages will change (sometimes by a lot)
and are not yet perfect, but we would rather leave this as is for later.
test results for running only the parser (excluding the variable binding
code) in a tight loop with inputs and parameters as given are promising:
- 40% faster on lix's package.nix at 10000 iterations
- 1.3% faster on nixpkgs all-packages.nix at 1000 iterations
- equivalent on all of nixpkgs concatenated at 100 iterations
(excluding invalid files, each file surrounded with parens)
more realistic benchmarks are somewhere in between the extremes, parsing
once again getting the largest uplift. other realistic workloads improve
by a few percentage points as well, notably system builds are 4% faster.
Benchmarks summary (from ./bench/summarize.jq bench/bench-*.json)
old/bin/nix --extra-experimental-features 'nix-command flakes' eval -f bench/nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix
mean: 0.408s ± 0.025s
user: 0.355s | system: 0.033s
median: 0.389s
range: 0.388s ... 0.442s
relative: 1
new/bin/nix --extra-experimental-features 'nix-command flakes' eval -f bench/nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix
mean: 0.332s ± 0.024s
user: 0.279s | system: 0.033s
median: 0.314s
range: 0.313s ... 0.361s
relative: 0.814
---
old/bin/nix --extra-experimental-features 'nix-command flakes' eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'
mean: 6.133s ± 0.022s
user: 5.395s | system: 0.437s
median: 6.128s
range: 6.099s ... 6.183s
relative: 1
new/bin/nix --extra-experimental-features 'nix-command flakes' eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'
mean: 5.925s ± 0.025s
user: 5.176s | system: 0.456s
median: 5.934s
range: 5.861s ... 5.943s
relative: 0.966
---
GC_INITIAL_HEAP_SIZE=10g old/bin/nix eval --extra-experimental-features 'nix-command flakes' --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'
mean: 4.503s ± 0.027s
user: 3.731s | system: 0.547s
median: 4.499s
range: 4.478s ... 4.541s
relative: 1
GC_INITIAL_HEAP_SIZE=10g new/bin/nix eval --extra-experimental-features 'nix-command flakes' --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'
mean: 4.285s ± 0.031s
user: 3.504s | system: 0.571s
median: 4.281s
range: 4.221s ... 4.328s
relative: 0.951
---
old/bin/nix --extra-experimental-features 'nix-command flakes' search --no-eval-cache github:nixos/nixpkgs/e1fa12d4f6c6fe19ccb59cac54b5b3f25e160870 hello
mean: 16.475s ± 0.07s
user: 14.088s | system: 1.572s
median: 16.495s
range: 16.351s ... 16.536s
relative: 1
new/bin/nix --extra-experimental-features 'nix-command flakes' search --no-eval-cache github:nixos/nixpkgs/e1fa12d4f6c6fe19ccb59cac54b5b3f25e160870 hello
mean: 15.973s ± 0.013s
user: 13.558s | system: 1.615s
median: 15.973s
range: 15.946s ... 15.99s
relative: 0.97
---
Change-Id: Ie66ec2d045dec964632c6541e25f8f0797319ee2
This reverts commit 35eec921af.
Reason for revert: Regressed nix-eval-jobs, and it appears to be this change is buggy/missing a case. It just needs another pass.
Code causing the problem in n-e-j, when invoked with `nix-eval-jobs --flake '.#hydraJobs'`:
```
n-e-j/tests/assets » ../../build/src/nix-eval-jobs --meta --workers 1 --flake .#hydraJobs
warning: unknown setting 'trusted-users'
warning: `--gc-roots-dir' not specified
error: unsupported Git input attribute 'dir'
error: worker error: error: unsupported Git input attribute 'dir'
```
```
nix::Value *vRoot = [&]() {
if (args.flake) {
auto [flakeRef, fragment, outputSpec] =
nix::parseFlakeRefWithFragmentAndExtendedOutputsSpec(
args.releaseExpr, nix::absPath("."));
nix::InstallableFlake flake{
{}, state, std::move(flakeRef), fragment, outputSpec,
{}, {}, args.lockFlags};
return flake.toValue(*state).first;
} else {
return releaseExprTopLevelValue(*state, autoArgs, args);
}
}();
```
Inspecting the program behaviour reveals that `dir` was in fact set in the URL going into the fetcher. This is in turn because unlike in the case changed in this commit, it was not erased before handing it to libfetchers, which is probably just a mistake.
```
(rr) up
3 0x00007ffff60262ae in nix::fetchers::Input::fromURL (url=..., requireTree=requireTree@entry=true) at src/libfetchers/fetchers.cc:39
warning: Source file is more recent than executable.
39 auto res = inputScheme->inputFromURL(url, requireTree);
(rr) p url
$1 = (const nix::ParsedURL &) @0x7fffdc874190: {url = "git+file:///home/jade/lix/nix-eval-jobs",
base = "git+file:///home/jade/lix/nix-eval-jobs", scheme = "git+file", authority = std::optional<std::string> = {[contained value] = ""},
path = "/home/jade/lix/nix-eval-jobs", query = std::map with 1 element = {["dir"] = "tests/assets"}, fragment = ""}
(rr) up
4 0x00007ffff789d904 in nix::parseFlakeRefWithFragment (url=".#hydraJobs", baseDir=std::optional<std::string> = {...},
allowMissing=allowMissing@entry=false, isFlake=isFlake@entry=true) at src/libexpr/flake/flakeref.cc:179
warning: Source file is more recent than executable.
179 FlakeRef(Input::fromURL(parsedURL, isFlake), getOr(parsedURL.query, "dir", "")),
(rr) p parsedURL
$2 = {url = "git+file:///home/jade/lix/nix-eval-jobs", base = "git+file:///home/jade/lix/nix-eval-jobs", scheme = "git+file",
authority = std::optional<std::string> = {[contained value] = ""}, path = "/home/jade/lix/nix-eval-jobs", query = std::map with 1 element = {
["dir"] = "tests/assets"}, fragment = ""}
(rr) list
174
175 if (pathExists(flakeRoot + "/.git/shallow"))
176 parsedURL.query.insert_or_assign("shallow", "1");
177
178 return std::make_pair(
179 FlakeRef(Input::fromURL(parsedURL, isFlake), getOr(parsedURL.query, "dir", "")),
180 fragment);
181 }
```
Change-Id: Ib55a882eaeb3e59228857761dc1e3b2e366b0f5e
On operating systems where /bin/sh is not Bash, some scripts are invalid
because of bashisms, and building Lix fails with errors like this:
`render-manpage.sh: 3: set: Illegal option -o pipefail`
This modifies all scripts that use a `/bin/sh` shebang to `/usr/bin/env
bash`, including currently POSIX-compliant ones, to prevent any future
confusion.
Change-Id: Ia074cc6db42d40fc59a63726f6194ea0149ea5e0
This is a squash of upstream PRs #10303, #10312 and #10883.
fix: Treat empty TMPDIR as unset
Fixes an instance of
nix: src/libutil/util.cc:139: nix::Path nix::canonPath(PathView, bool): Assertion `path != ""' failed.
... which I've been getting in one of my shells for some reason.
I have yet to find out why TMPDIR was empty, but it's no reason for
Nix to break.
(cherry picked from commit c3fb2aa1f9d1fa756dac38d3588c836c5a5395dc)
fix: Treat empty XDG_RUNTIME_DIR as unset
See preceding commit. Not observed in the wild, but is sensible
and consistent with TMPDIR behavior.
(cherry picked from commit b9e7f5aa2df3f0e223f5c44b8089cbf9b81be691)
local-derivation-goal.cc: Reuse defaultTempDir()
(cherry picked from commit fd31945742710984de22805ee8d97fbd83c3f8eb)
fix: remove usage of XDG_RUNTIME_DIR for TMP
(cherry picked from commit 1363f51bcb24ab9948b7b5093490a009947f7453)
tests/functional: Add count()
(cherry picked from commit 6221770c9de4d28137206bdcd1a67eea12e1e499)
Remove uncalled for message
(cherry picked from commit b1fe388d33530f0157dcf9f461348b61eda13228)
Add build-dir setting
(cherry picked from commit 8b16cced18925aa612049d08d5e78eccbf0530e4)
Change-Id: Ic7b75ff0b6a3b19e50a4ac8ff2d70f15c683c16a
this is only used in one place, and only to set a nicer error message on
EndOfFile. the only caller that actually *catches* this exception should
provide an error message in that catch block rather than forcing support
for setting error message so deep into the stack. copyStorePath is never
called outside of PathSubstitutionGoal anyway, which catches everything.
Change-Id: Ifbae8706d781c388737706faf4c8a8b7917ca278
The original idea was to fix lix#174, but for a user friendly solution,
I figured that we'd need more consistency:
* Invalid query params will cause an error, just like invalid
attributes. This has the following two consequences:
* The `?dir=`-param from flakes will be removed before the URL to be
fetched is passed to libfetchers.
* The tarball fetcher doesn't allow URLs with custom query params
anymore. I think this was questionable anyways given that an
arbitrary set of query params was silently removed from the URL you
wanted to fetch. The correct way is to use an attribute-set
with a key `url` that contains the tarball URL to fetch.
* Same for the git & mercurial fetchers: in that case it doesn't even
matter though: both fetchers added unused query params to the URL
that's passed from the input scheme to the fetcher (`url2` in the code).
It turns out that this was never used since the query parameters were
erased again in `getActualUrl`.
* Validation happens for both attributes and URLs. Previously, a lot of
fetchers validated e.g. refs/revs only when specified in a URL and
the validity of attribute names only in `inputFromAttrs`.
Now, all the validation is done in `inputFromAttrs` and `inputFromURL`
constructs attributes that will be passed to `inputFromAttrs`.
* Accept all attributes as URL query parameters. That also includes
lesser used ones such as `narHash`.
And "output" attributes like `lastModified`: these could be declared
already when declaring inputs as attribute rather than URL. Now the
behavior is at least consistent.
Personally, I think we should differentiate in the future between
"fetched input" (basically the attr-set that ends up in the lock-file)
and "unfetched input" earlier: both inputFrom{Attrs,URL} entrypoints
are probably OK for unfetched inputs, but for locked/fetched inputs
a custom entrypoint should be used. Then, the current entrypoints
wouldn't have to allow these attributes anymore.
Change-Id: I1be1992249f7af8287cfc37891ab505ddaa2e8cd
Unfetched submodules are included as empty directories in archives, so they end
up as such in the store when fetched in clean mode. Make sure the same happens
in dirty mode too. Fortunately, they are already correctly represented in the
ls-files output, so we just need to make sure to include the empty directory in
our filter.
Fixes: https://github.com/NixOS/nix/issues/6247
Change-Id: I60d06ff360cfa305d081b920838c893c06da801c
This seems to have been caused by having the wrong PID. I don't know why
it worked before in the sandbox, but the code was definitely wrong
before, so let's just fix it.
Change-Id: I556580bdf614c716566310e975a36daa6d6c9a91
Followup to https://gerrit.lix.systems/c/lix/+/1417 to ensure that this
parser will never take something that doesn't look like a version.
It turns out this problem is less alarming than initially thought
because it only applies to the testsuite in a non-default mode.
Change-Id: I26aba24aaf0215f2b782966314b94784db766266
Since ad8a4b380e, the version printer returns "nix (Lix, like Nix) 2.x",
hence the `daemonVersion` was being set to the string "like".
Using `compareVersions` with a letter compares them lexicographically:
builtins.compareVersions "like" "2.12pre20230103" // => -1
builtins.compareVersions "like" "2.16.0" // => -1
This caused that `isDaemonNewer` always returned 1, falsy in Bash terms.
Therefore, the test suite skipped those tests where they use it.
Fixes lix-project/lix#324
Change-Id: If6682515bf0bf8b8add641af9a4e98b50a9acb51
Here's my guide so far:
$ rg '((?!(recursive).*) Nix
(?!(daemon|store|expression|Rocks!|Packages|language|derivation|archive|account|user|sandbox|flake).*))'
-g '!doc/' --pcre2
All items from this query have been tackled. For the documentation side:
that's for lix-project/lix#162.
Additionally, all remaining references to github.com/NixOS/nix which
were not relevant were also replaced.
Fixes: lix-project/lix#148.
Fixes: lix-project/lix#162.
Change-Id: Ib3451fae5cb8ab8cd9ac9e4e4551284ee6794545
Signed-off-by: Raito Bezarius <raito@lix.systems>
* changes:
util.hh: Delete remaining file and clean up headers
util.hh: Move nativeSystem to local-derivation-goal.cc
util.hh: Move stuff to types.hh
util.cc: Delete remaining file
util.{hh,cc}: Move ignoreException to error.{hh,cc}
util.{hh,cc}: Split out namespaces.{hh,cc}
util.{hh,cc}: Split out users.{hh,cc}
util.{hh,cc}: Split out strings.{hh,cc}
util.{hh,cc}: Split out unix-domain-socket.{hh,cc}
util.{hh,cc}: Split out child.{hh,cc}
util.{hh,cc}: Split out current-process.{hh,cc}
util.{hh,cc}: Split out processes.{hh,cc}
util.{hh,cc}: Split out file-descriptor.{hh,cc}
util.{hh,cc}: Split out file-system.{hh,cc}
util.{hh,cc}: Split out terminal.{hh,cc}
util.{hh,cc}: Split out environment-variables.{hh,cc}
grepQuietInvert is a typo introduced by c11836126b.
The test functional-timeout was failing silently because Bash considered
the command-not-found error as truthy.
Change-Id: Ic13829d02ec55d6ecd63a0f4d34ec0d32379609f
Fixes#183, #110, #116.
The default flake-registry option becomes 'vendored', and refers
to a vendored flake-registry.json file in the install path.
Vendored copy of the flake-registry is from github:NixOS/flake-registry
at commit 9c69f7bd2363e71fe5cd7f608113290c7614dcdd.
Change-Id: I752b81c85ebeaab4e582ac01c239d69d65580f37
Basically I'd expect the same behavior as with `nix-build`, i.e.
with `--keep-going` the hash-mismatch error of each failing
fixed-output derivation is shown.
The approach is derived from `Store::buildPaths` (`entry-point.cc`):
instead of throwing the first build-result, check if there are any build
errors and if so, display all of them and throw after that.
Unfortunately, the BuildResult struct doesn't have an `ErrorInfo`
(there's a FIXME for that at least), so I have to construct my own here.
This is a rather cheap bugfix and I decided against touching too many
parts of libstore for that (also I don't know if that's in line with the
ongoing refactoring work).
Closes lix-project/lix#302
Change-Id: I378ab984fa271e6808c6897c45e0f070eb4c6fac